Martian meteorite NWA 7034, nicknamed "Black Beauty," weighs approximately 320 g (11 oz).
A Martian meteorite is a rock that formed on Mars, was ejected from the planet by an impact event, and traversed interplanetary space before landing on Earth as a meteorite. As of September 2020, 277 meteorites had been classified as Martian, less than half a percent of the 72,000 meteorites that have been classified.
By
the early 1980s, it was obvious that the SNC group of meteorites
(Shergottites, Nakhlites, Chassignites) were significantly different
from most other meteorite types. Among these differences were younger
formation ages, a different oxygen isotopic composition, the presence of
aqueous weathering products, and some similarity in chemical
composition to analyses of the Martian surface rocks in 1976 by the Viking landers.
Several scientists suggested these characteristics implied the origin
of SNC meteorites from a relatively large parent body, possibly Mars.
Then in 1983, various trapped gases were reported in impact-formed
glass of the EET79001 shergottite, gases which closely resembled those
in the Martian atmosphere as analyzed by Viking.
These trapped gases provided direct evidence for a Martian origin. In
2000, an article by Treiman, Gleason and Bogard gave a survey of all the
arguments used to conclude the SNC meteorites (of which 14 had been
found at the time) were from Mars. They wrote, "There seems little
likelihood that the SNCs are not from Mars. If they were from another
planetary body, it would have to be substantially identical to Mars as
it now is understood."
Subdivision
The Martian meteorites are divided into three groups (orange) and two grouplets (yellow). SHE = Shergottite, NAK = Nakhlite, CHA = Chassignite, OPX = Orthopyroxenite (ALH 84001), BBR = Basaltic Breccia (NWA 7034).
As of April 25, 2018, 192 of the 207 Martian meteorites are divided into three rare groups of achondritic (stony) meteorites: shergottites (169), nakhlites (20), chassignites
(3), and ones otherwise (15) (containing the orthopyroxenite (OPX)
Allan Hills 84001, as well as 10 basaltic breccia meteorites). Consequently, Martian meteorites as a whole are sometimes referred to as the SNC group. They have isotope
ratios that are said to be consistent with each other and inconsistent
with the Earth. The names derive from the location of where the first
meteorite of their type was discovered.
Shergottites
Roughly three-quarters of all Martian meteorites can be classified as shergottites. They are named after the Shergotty meteorite, which fell at Sherghati, India in 1865. Shergottites are igneous rocks of mafic to ultramaficlithology. They fall into three main groups, the basaltic, olivine-phyric (such as the Tissint group found in Morocco in 2011) and Lherzolitic
shergottites, based on their crystal size and mineral content. They can
be categorised alternatively into three or four groups based on their rare-earth element content.
These two classification systems do not line up with each other,
hinting at complex relationships between the various source rocks and
magmas from which the shergottites formed.
NWA 6963, a shergottite found in Morocco, September 2011.
The shergottites appear to have crystallised as recently as 180 million years ago,
which is a surprisingly young age considering how ancient the majority
of the surface of Mars appears to be, and the small size of Mars itself.
Because of this, some have advocated the idea that the shergottites are
much older than this. This "Shergottite Age Paradox" remains unsolved and is still an area of active research and debate.
The 3-million-year-old crater Mojave,
58.5 km in diameter and the youngest crater of its size on the planet,
has been identified as a potential source of these meteorites.
Nakhlites
Nakhla meteorite's two sides and its inner surfaces after breaking it
Nakhlites are igneous rocks that are rich in augite and were formed from basalticmagma from at least four eruptions, spanning around 90 million years, from 1416 ± 7 to 1322 ± 10 million years ago. They contain augite and olivinecrystals.
Their crystallization ages, compared to a crater count chronology of
different regions on Mars, suggest the nakhlites formed on the large
volcanic construct of either Tharsis, Elysium, or Syrtis Major Planum.
It has been shown that the nakhlites were suffused with liquid
water around 620 million years ago and that they were ejected from Mars
around 10.75 million years ago by an asteroid impact. They fell to Earth
within the last 10,000 years.
Chassignites
The first chassignite, the Chassigny meteorite, fell at Chassigny, Haute-Marne, France in 1815. There has been only one other chassignite recovered, named Northwest Africa (NWA) 2737. NWA 2737 was found in Morocco or Western Sahara
in August 2000 by meteorite hunters Bruno Fectay and Carine Bidaut, who
gave it the temporary name "Diderot." It was shown by Beck et al. that its "mineralogy, major and trace element chemistry as well as oxygen isotopes revealed an unambiguous Martian origin and strong affinities with Chassigny."
Among these, the famous specimen Allan Hills 84001 has a different rock type from other Martian meteorites: it is an orthopyroxenite (an igneous rock dominantly composed of orthopyroxene).
For this reason it is classified within its own group, the "OPX Martian
meteorites". This meteorite received much attention after an electron
microscope revealed structures that were considered to be the fossilized remains of bacteria-like lifeforms. As of 2005, scientific consensus was that the microfossils were not indicative of Martian life, but of contamination by earthly biofilms. ALH 84001 is as old as the basaltic and intermediate shergottite groups – i.e., 4.1 billion years old.
In March 2004 it was suggested that the unique Kaidun meteorite, which landed in Yemen on December 3, 1980, may have originated on the Martian moon of Phobos. Because Phobos has similarities to C-type asteroids and because the Kaidun meteorite is a carbonaceous chondrite,
Kaidun is not a Martian meteorite in the strict sense. However, it may
contain small fragments of material from the Martian surface.
The Martian meteorite NWA 7034 (nicknamed "Black Beauty"), found in the Sahara desert during 2011, has ten times the water content of other Mars meteorites found on Earth. The meteorite contains components as old as 4.42 ± 0.07 Ga (billion years), and was heated during the Amazonian geologic period on Mars.
Origin
The majority of SNC meteorites are quite young compared to most other meteorites and seem to imply that volcanic
activity was present on Mars only a few hundred million years ago. The
young formation ages of Martian meteorites was one of the early
recognized characteristics that suggested their origin from a planetary
body such as Mars. Among Martian meteorites, only ALH 84001 and NWA 7034
have radiometric ages older than about 1400 Ma (Ma = million years).
All nakhlites, as well as Chassigny and NWA 2737, give similar if not
identical formation ages around 1300 Ma, as determined by various
radiometric dating techniques. Formation ages determined for many shergottites are variable and much younger, mostly ~150-575 Ma.
The chronological history of shergottites is not totally understood,
and a few scientists have suggested that some may actually have formed
prior to the times given by their radiometric ages,
a suggestion not accepted by most scientists. Formation ages of SNC
meteorites are often linked to their cosmic-ray exposure (CRE) ages, as
measured from the nuclear products of interactions of the meteorite in
space with energetic cosmic ray
particles. Thus, all measured nakhlites give essentially identical CRE
ages of approximately 11 Ma, which when combined with their possible
identical formation ages indicates ejection of nakhlites into space from
a single location on Mars by a single impact event.
Some of the shergottites also seem to form distinct groups according to
their CRE ages and formation ages, again indicating ejection of several
different shergottites from Mars by a single impact. However, CRE ages
of shergottites vary considerably (~0.5–19 Ma),
and several impact events are required to eject all the known
shergottites. It had been asserted that there are no large young craters
on Mars that are candidates as sources for the Martian meteorites, but
subsequent studies claimed to have a likely source for ALH 84001 and a possible source for other shergottites.
In a 2014 paper, several researchers claimed that all shergottites meteorites come from the Mojave Crater on Mars.
Age estimates based on cosmic ray exposure
A Martian meteorite crafted into a small pendant and suspended from a silver necklace.
The amount of time spent in transit from Mars to Earth can be
estimated by measurements of the effect of cosmic radiation on the
meteorites, particularly on isotope ratios of noble gases. The meteorites cluster in families that seem to correspond to distinct impact events on Mars.
It is thought, therefore, that the meteorites all originate in
relatively few impacts every few million years on Mars. The impactors
would be kilometers in diameter and the craters they form on Mars tens
of kilometers in diameter. Models of impacts on Mars are consistent with
these findings.
Several
Martian meteorites have been found to contain what some think is
evidence for fossilized Martian life forms. The most significant of
these is a meteorite found in the Allan Hills of Antarctica (ALH 84001).
Ejection from Mars seems to have taken place about 16 million years
ago. Arrival on Earth was about 13 000 years ago. Cracks in the rock
appear to have filled with carbonate materials (implying groundwater was
present) between 4 and 3.6 billion-years-ago. Evidence of polycyclic aromatic hydrocarbons
(PAHs) have been identified with the levels increasing away from the
surface. Other Antarctic meteorites do not contain PAHs. Earthly
contamination should presumably be highest at the surface. Several
minerals in the crack fill are deposited in phases, specifically, iron deposited as magnetite, that are claimed to be typical of biodepositation on Earth. There are also small ovoid and tubular structures that might be nanobacteriafossils in carbonate material in crack fills (investigators McKay, Gibson, Thomas-Keprta, Zare). Micropaleontologist
Schopf, who described several important terrestrial bacterial
assemblages, examined ALH 84001 and opined that the structures are too
small to be Earthly bacteria and don't look especially like lifeforms to
him. The size of the objects is consistent with Earthly "nanobacteria", but the existence of nanobacteria itself is controversial.
Many studies disputed the validity of the fossils. For example, it was found that most of the organic matter in the meteorite was of terrestrial origin. But, a recent study suggests that magnetite
in the meteorite could have been produced by Martian microbes. The
study, published in the journal of the Geochemical and Meteoritic
Society, used more advanced high resolution electron microscopy than was
possible in 1996.
A serious difficulty with the claims for a biogenic origin of the
magnetites is that the majority of them exhibit topotactic
crystallographic relationships with the host carbonates (i.e., there are
3D orientation relationships between the magnetite and carbonate
lattices), which is strongly indicative that the magnetites have grown
in-situ by a physico-chemical mechanism.
While water is no indication of life, many of the meteorites
found on Earth have shown water, including NWA 7034 which formed during
the Amazonian period of Martian geological history. Other signs of surface liquid water on Mars (such as recurring slope lineae)
are a topic of debate among planetary scientists, but generally
consistent with the earlier evidence provided by martian meteorites. Any
liquid water present is likely too minimal to support life.
The initial variant of SLS, Block 1, was required by the U.S. Congress to lift a payload of 70 t (69 long tons; 77 short tons) to low Earth orbit
(LEO), but it was later planned to exceed that requirement with a rated
payload capacity of 95 t (93 long tons; 105 short tons). As of 22 December 2019, this variant is planned to launch Artemis 1, Artemis 2, and Artemis 3. The later Block 1B is intended to debut the Exploration Upper Stage and launch the notional Artemis 4 through Artemis 7.
Block 2 is planned to replace the initial Shuttle-derived boosters with
advanced boosters and would have a LEO capability of more than 130 t
(130 long tons; 140 short tons), again as required by Congress. Block 2 is intended to enable crewed launches to Mars.
As of 2018, SLS was planned to have the world's highest-ever total LEO payload capability, but not the world's highest ever injection mass. The SLS is planned to launch the Orion spacecraft and use the ground operations and launch facilities at NASA's Kennedy Space Center in Florida. The rocket will use the Launch Complex 39B at the Kennedy Space Center. The first launch is currently scheduled for 4 November 2021.
Vehicle description
The SLS is a Space Shuttle-derived launch vehicle, with the first stage of the rocket being powered by one central core stage and two outboard boosters. The upper stage is being developed from the Block 1 variant to a Block 1B and 2 variant, the Exploration Upper Stage.
Core stage
The Space Launch System's core stage contains the Main Propulsion System (MPS) of the launch vehicle. It is 65 m (212 ft) long by 8.4 m (27.6 ft) in diameter and fuels the four RS-25 rocket engines at its base. The core stage is structurally and visually similar to the Space Shuttle external tank, containing the liquid hydrogenfuel and liquid oxygenoxidizer. Flights 1 through 4 are planned to use modified RS-25D engines left over from the Space Shuttle program.
However, the RS-25 engines were designed with reuse in mind for the
Space Shuttle, so later flights are planned to switch to a expendable
optimized RS-25 variant, lowering per engine costs over 30%.
The core stage is fabricated at NASA's Michoud Assembly Facility and is common across all currently planned evolutions of the SLS to avoid the need for redesigns to meet varying requirements.
Blocks 1 and 1B of the SLS are planned to use two five-segmentSolid Rocket Boosters (SRBs). These new SRBs are derived from the four-segment Space Shuttle Solid Rocket Boosters, with the addition of a center booster segment, new avionics, and lighter insulation.
The five-segment SRBs provide approximately 25% more total impulse than
the Shuttle SRB, but will no longer be recovered after use.
Booster Obsolescence and Life Extension program
The stock of SLS boosters is limited by the number of casings left over from the Shuttle program, since they
modify flown boosters to add an additional segment. There are enough to
last through eight flights of the SLS, but a replacement will be
required for further flights.
On 2 March 2019, the Booster Obsolescence and Life Extension (BOLE)
program was announced. This program will use new solid rocket boosters
built by Northrop Grumman Innovation Systems for further SLS flights. These boosters would be derived from the composite-casing SRBs in development for the OmegA launch vehicle before it was canceled, and are projected to increase Block 1B's payload to TLI by 3–4 metric tons, which is still 1 ton below the payload capacity of Block 2.
Block 2 – advanced boosters
Block
2 will have special advanced boosters which will enable Block 2 to
carry 130 metric tons (130 long tons; 140 short tons) to LEO and at
least 46 metric tons (45 long tons; 51 short tons) to TLI.
Upper stage
ICPS – Block 1
The Interim Cryogenic Propulsion Stage (ICPS) is planned to fly on Artemis 1. It is a stretched and human-rated Delta IV 5-meter (16 ft) Delta Cryogenic Second Stage (DCSS) powered by a single RL10B-2 engine. Block 1 is intended to be capable of lifting 95 tonnes to low Earth orbit (LEO) in this configuration if the ICPS is considered part of the payload. Artemis 1 is to be launched into an initial 1,800 by −93 km (1,118 by −58 mi) suborbital
trajectory to ensure safe disposal of the core stage. ICPS will then
perform an orbital insertion burn at apogee and a subsequent translunar injection burn to send Orion towards the Moon. The ICPS for Artemis 1 was delivered by ULA to NASA about July 2017, and was housed at Kennedy Space Centre as of November 2018. As of February 2020, ICPS (not EUS) is planned for Artemis 1, 2, and 3. ICPS will be human-rated for the crewed Artemis 2 flight.
EUS – Block 1B and 2
The Exploration Upper Stage (EUS) is planned to fly on Artemis 4. Similar to the S-IVB, the EUS will complete the SLS ascent phase and then re-ignite to send its payload to destinations beyond LEO.
It is expected to be used by Block 1B and Block 2, share the core stage
diameter of 8.4 meters, and be powered by four RL10C-3 engines. It will eventually be upgraded to use four RL10C-X engines instead.
Payload carrying capacity
Resilience
The
SLS is planned to have the ability to tolerate 23 tanking cycles, 13
are reserved for launch attempts on Artemis 1. The assembled rocket is
to be able to remain at the launch pad for at least 180 days and can
remain in a stacked configuration for at least 200 days.
Development history
Planned evolution of the Space Launch System, 2018
Program history
During
the joint Senate-NASA presentation in September 2011, it was stated
that the SLS program had a projected development cost of US$18 billion
through 2017, with US$10 billion for the SLS rocket, US$6 billion for
the Orion spacecraft and US$2 billion for upgrades to the launch pad and other facilities at Kennedy Space Center. These costs and schedule were considered optimistic in an independent 2011 cost assessment report by Booz Allen Hamilton for NASA.
An internal 2011 NASA document estimated the cost of the program
through 2025 to total at least $41 billion for four 95-tonne launches (1
uncrewed, 3 crewed), with the 130-tonne version ready no earlier than 2030.
The Human Exploration Framework Team (HEFT) estimated unit costs
for Block 0 at US$1.6 billion and Block 1 at US$1.86 billion in 2010. However, since these estimates were made the Block 0 SLS vehicle was dropped in late 2011, and the design was not completed.
In September 2012, an SLS deputy project manager stated that US$500 million per launch is a reasonable target cost for SLS.
In 2013, the Space Review estimated the cost per launch at US$5 billion, depending on the rate of launches. NASA announced in 2013 that the European Space Agency (ESA) will build the Orion service module.
In 2011, NASA announced an "Advanced Booster Competition", to be
decided in 2015, which would select whose boosters would be used for
Block 2 of the SLS.
Several companies proposed boosters for this competition:
Aerojet, in partnership with Teledyne Brown, offered a booster powered by three new AJ1E6 LOX/RP-1oxidizer-rich staged combustion engines, each producing 4,900 kN (1,100,000 lbf) thrust using a single turbopump to supply dual combustion chambers.
On 14 February 2013, Aerojet was awarded a US$23.3 million, 30-month
contract to build a 2,400 kN (550,000 lbf) main injector and thrust
chamber.
Alliant Techsystems
(ATK) proposed an advanced SRB nicknamed "Dark Knight", which would
switch to a lighter composite case, use a more energetic propellant, and
reduce the number of segments from five to four.
In 2013, the manager of NASA's SLS advanced development office indicated that all three approaches were viable.
However, this competition was planned for a development plan in
which Block 1A would be followed by Block 2A, with upgraded boosters.
NASA canceled Block 1A and the planned competition in April 2014.
Due to this cancellation, it was reported in February 2015 that SLS is
expected to fly with the original five-segment SRB until at least the
late 2020s. This decision was vindicated as a later study found that the
advanced booster would have resulted in unsuitably high acceleration. The overly powerful booster would need modifications to Launch Pad 39B (LC-39B), its flame trench, and Mobile Launcher, which are being evaluated.
In August 2014, as the SLS program passed its Key Decision Point
C review and entered full development, costs from February 2014 until
its planned launch in September 2018 were estimated at US$7.021 billion. Ground systems modifications and construction would require an additional US$1.8 billion over the same time period.
In October 2018, NASA's inspector general reported that the
Boeing core stage contract had made up 40% of the US$11.9 billion spent
on SLS as of August 2018. By 2021, core stages were expected to have
cost a total of US$8.9 billion, which is twice the initially planned
amount.
In December 2018, NASA estimated that yearly budgets for SLS will range from US$2.1 to US$2.3 billion between 2019 and 2023.
In March 2019, the Trump Administration released its Fiscal Year 2020 Budget Request
for NASA. This budget did not include any money for the Block 1B and
Block 2 variants of SLS. It was therefore uncertain whether these future
variants of SLS will be developed, but congressional action restored
this funding in the passed budget. Several launches previously planned for the SLS Block 1B are now expected to fly on commercial launcher vehicles such as Falcon Heavy, New Glenn and Vulcan.
However, the request for a budget increase of US$1.6 billion towards
SLS, Orion, and crewed landers along with the launch manifest seem to
indicate support of the development of Block 1B, debuting Artemis 3. The
Block 1B will be used mainly for co-manifested crew transfers and
logistical needs rather than constructing the Gateway. An uncrewed Block
1B is planned to launch the Lunar Surface Asset in 2028, the first
lunar outpost of the Artemis program. Block 2 development will most
likely start in the late 2020s after NASA is regularly visiting the
lunar surface and shifts focus towards Mars.
Blue Origin
submitted a proposal to replace the Exploration Upper Stage with an
alternative to be designed and fabricated by the company, but it was
rejected by NASA in November 2019 on multiple grounds. These included
lower performance compared to the existing EUS design, unsuitability of
the proposal to current ground infrastructure, and unacceptable
acceleration in regards to Orion components.
On March 18th 2021, CS-1 successfully completed its 8 minute Green Run test.
Funding history
For fiscal years 2011 through 2020, the SLS program had expended
funding totaling US$18.648 billion in nominal dollars. This is
equivalent to US$20.314 billion in 2020 dollars using the NASA New Start
Inflation Indices.
For fiscal year 2021, US$2.257 billion.
Fiscal year
Funding (millions)
Status
Nominal
In US$2020
2011
US$1,536.1
US$1,819.9
Actual (Formal SLS Program reporting excludes the Fiscal 2011 budget.)
2012
US$1,497.5
US$1,755.5
Actual
2013
US$1,414.9
US$1,634.1
Actual
2014
US$1,600.0
US$1,812.3
Actual
2015
US$1,678.6
US$1,863.8
Actual
2016
US$1,971.9
US$2,159.6
Actual
2017
US$2,127.1
US$2,286.8
Actual
2018
US$2,150.0
US$2,256.6
Actual
2019
US$2,144.0
US$2,199.9
Actual
2020
US$2,525.8
US$2,525.8
Enacted
2021
US$2,585.9
US$2,585.9
Enacted
2011–2020
Total: US$18,648
Total: US$20,314
On top of this, the costs to assemble, integrate, prepare and launch the SLS and its payloads are funded separately under Exploration Ground Systems, currently about US$600 million per year.
Excluded from the above SLS costs are:
Costs of payloads for the SLS (such as Orion crew capsule)
Costs of the predecessor Ares V / Cargo Launch Vehicle (funded from 2008 to 2010)
Costs for the Ares I / Crew Launch Vehicle (funded from 2006 to 2010, a total of US$4.8 billion in development that included the 5-segment Solid Rocket Boosters that will be used on the SLS)
Included in the above SLS costs are:
Costs of the interim Upper Stage for the SLS, the Interim
Cryogenic Propulsion Stage (ICPS) for SLS, which includes a US$412
million contract
Costs of the future Upper Stage for the SLS, the Exploration Upper Stage (EUS) (funded at US$85 million in 2016, US$300 million in 2017, US$300 million in 2018, and US$150 million in 2019)
Per launch costs
The
per launch costs for SLS have varied widely, partly due to uncertainty
over how much the program will expend during development and testing
before the operational launches begin, and partly due to various
agencies using differing cost measures (for example, a marginal cost per one additional launch, which ignores development and annual recurring fixed costs vs. total cost
per launch, including recurring costs but excluding development); but
also based on differing purposes for which the cost estimates were
developed.
There are no official NASA estimates for how much SLS will cost
per launch, nor for the SLS program annual recurring costs once
operational. Cost per launch is not a straightforward figure to estimate
as it depends heavily on how many launches occur per year. For example, similarly, the Space Shuttle
was estimated (in 2012 dollars) to cost US$576 million per launch had
it been able to achieve 7 launches per year, while the marginal cost of
adding a single additional launch in a given year was estimated to be
less than half of that, at just US$252 million of marginal cost.
However, at the rate that it actually flew, the cost in the end was
US$1.64 billion per Space Shuttle launch, including development.
Several internal NASA programs and project concept study reports
have released proposed budgets that include future SLS launches. For
example, a concept study report for a space telescope was advised by NASA HQ in 2019 to budget US$500 million for an SLS launch in 2035.
Another study in 2019 also proposing a space telescope assumed a budget
for their launch of US$650 million in current day dollars, or US$925
million for when the launch would occur, which is also in the
"mid-2030s".
Europa Clipper
is a NASA scientific mission that was required by Congress to launch on
the SLS. Oversight bodies both internal and external to NASA disagreed
with this requirement. First, NASA's Inspector General office published a
report in May 2019
that stated Europa Clipper would need to give up US$876 million for the
"marginal cost" of its SLS launch. Then, an addendum to the letter
published in August 2019 increased the estimate and stated that
switching to a commercial rocket would actually save over US$1 billion.
(Although this savings may have included a portion of costs related to
the delay in launch schedule; a commercial alternative could launch
sooner than SLS) A JCL (Joint Cost and Schedule Confidence Level)
analysis cited in that letter put the cost savings at US$700 million,
with SLS at US$1.05 billion per launch and the commercial alternative at
US$350 million.
Finally, a letter from the White House Office of Management and
Budget (OMB) to the Senate Appropriations Committee in October 2019
revealed that SLS's total cost to the taxpayer was estimated at "over
US$2 billion" per launch after development is complete (program
development has cost US$20 billion to date in 2020 dollars).
The letter urged Congress to remove this requirement, in agreement with
the NASA Inspector General, adding that using a commercial launch
vehicle for Europa Clipper instead of SLS would save US$1.5 billion
overall. NASA did not deny this US$2 billion cost of launch and an
agency spokesperson stated it "is working to bring down the cost of a
single SLS launch in a given year as the agency continues negotiations
with Boeing on the long-term production contract and efforts to finalize
contracts and costs for other elements of the rocket". This OMB figure is dependent on the rate of construction, so building more SLS rockets faster could decrease the per-unit cost. For example, Exploration Ground Systems
– whose only role is to support, assemble, integrate, and launch SLS –
has separately budgeted fixed costs of US$600 million per year on
facilities, spread across however many rockets launch that year. Then NASA Administrator Jim Bridenstine
shared informally that he disagrees with the US$2 billion figure since
the marginal cost of an SLS launch should decrease after the first few,
and is expected to end up around US$800 million to US$900 million,
although contract negotiations were only just beginning for those later
cores.
On 1 May 2020, NASA awarded a contract extension to Aerojet Rocketdyne
to manufacture 18 additional RS-25 engines with associated services for
US$1.79 billion, bringing the total RS-25 contract value to almost
US$3.5 billion.
Constellation
From
2009 to 2011, three full-duration static fire tests of five-segment
SRBs were conducted under the Constellation Program, including tests at
low and high core temperatures, to validate performance at extreme
temperatures. The 5-segment SRB would be carried over to SLS.
Engineers
with Exploration Ground Systems and Jacobs prepare to lift and place
the core stage of the Space Launch System rocket for the Artemis I
mission on the mobile launcher and in-between the already assembled twin
rocket boosters.
During the early development of the SLS a number of configurations
were considered, including a Block 0 variant with three main engines, a Block 1A variant with upgraded boosters instead of the improved second stage, and a Block 2 with five main engines and the Earth Departure Stage, with up to three J-2X engines.
In February 2015, it was determined that these concepts would exceed
the congressionally mandated Block 1 and Block 1B baseline payloads.
On 14 September 2011, NASA announced the new launch system,
which is intended to take the agency's astronauts farther into space
than ever before and provide the cornerstone for future U.S. human space
exploration efforts in combination with the Orion spacecraft.
On 31 July 2013, the SLS passed the Preliminary Design Review
(PDR). The review included not only the rocket and boosters but also
ground support and logistical arrangements.
On 7 August 2014, the SLS Block 1 passed a milestone known as Key
Decision Point C and entered full-scale development, with an estimated
launch date of November 2018.
In 2013, NASA and Boeing
analyzed the performance of several EUS engine options. The analysis
was based on a second-stage usable propellant load of 105 metric tons,
and compared stages with four RL10 engines, two MARC-60 engines, or one J-2X engine.
In 2014, NASA also considered using the European Vinci
instead of the RL10. The Vinci offers the same specific impulse but
with 64% greater thrust, which would allow for the same performance at
lower cost.
Northrop Grumman Innovation Systems
has completed full-duration static fire tests of the five-segment SRBs.
Qualification Motor 1 (QM-1) was tested on 10 March 2015. Qualification Motor 2 (QM-2) was successfully tested on 28 June 2016.
SLS History
Artemis I core stage going into the Vehicle Assembly Building
As of 2020, three SLS versions are planned: Block 1, Block 1B, and
Block 2. Each will use the same core stage with four main engines, but
Block 1B will feature the Exploration Upper Stage (EUS), and Block 2 will combine the EUS with upgraded boosters.
In mid-November 2014, construction of the first core stage
hardware began using a new welding system in the South Vertical Assembly
Building at NASA's Michoud Assembly Facility. Between 2015 and 2017, NASA test fired RS-25 engines in preparation for use on SLS.
As of late 2015, the SLS program was stated to have a 70% confidence level for the first crewed Orion flight by 2023, and as of 2020, NASA is continuing to project a 2023 launch.
A test article build for the core stage began on 5 January 2016 and was expected to be completed in late January 2016. Once completed the test article was to be sent to ensure structural integrity at Marshall Space Flight Center. A structural test article of the ICPS was delivered in 2015. the core stage for Artemis 1 completed assembly in November 2019.
The first core stage left Michoud for comprehensive testing at Stennis in January 2020. The static firing test program at Stennis Space Center, known as the Green Run, will operate all the core stage systems simultaneously for the first time.
Test 7 (of 8), the wet dress rehearsal, was carried out in December
2020 and the hot fire (test 8) took place on 16 January 2021, but shut
down earlier than expected,
about 67 seconds in total rather than the desired eight minutes. The
reason for the early shutdown was later reported to be because of
conservative test commit criteria on the thrust vector control system,
specific only for ground testing and not for flight. If this scenario
occurred during a flight, the rocket would have continued to fly
normally. There was no sign of damage to the core stage or the engines,
contrary to initial concerns.
The second hot fire test was successfully completed March 18, with all 4
engines igniting, throttling down as expected to simulate in-flight
conditions, and gimballing profiles.
The core stage was shipped down to Kennedy Space Center to be mated with the rest of the rocket for Artemis 1. It left Stennis on April 24, and arrived at Kennedy on April 27. It was refurbished there in preparation for stacking.
On 12 June 2021, NASA announced the assembly of the first SLS rocket
was completed at the Kennedy Space Center. The assembled SLS is planned
to be used for the unmanned Artemis 1 mission later in 2021.
The intended uncrewed first flight of SLS has slipped multiple times: originally from late 2016 to October 2017, then to November 2018, then to 2019, then to June 2020, then to April 2021, and most recently to November 2021.
Criticism
NASA
moved out US$889 million of costs relating to SLS boosters, but did not
update the SLS budget to match, a March 2020 Inspector General report
found. This kept the budget overrun to 15% by FY 2019. At 30%, NASA would have to notify Congress and stop funding unless Congress reapproves and provides additional funding. The Inspector General report found that were it not for this "masking" of cost, the overrun would be 33% by FY 2019. The GAO separately stated "NASA's current approach for reporting cost growth misrepresents the cost performance of the program".
The SLS has been criticized on the basis of program cost, lack of
commercial involvement, and the non-competitive nature of a vehicle
legislated to use Space Shuttle components.
In 2009, the Augustine commission
proposed a commercial 75 t (74 long tons; 83 short tons) launcher with
lower operating costs, and noted that a 40–60 t (39–59 long tons; 44–66
short tons) launcher was the minimum required to support lunar
exploration.
In 2011–2012, the Space Access Society, Space Frontier Foundation and The Planetary Society called for the cancellation of the project, arguing that SLS will consume the funds for other projects from the NASA budget. U.S. RepresentativeDana Rohrabacher and others proposed that an orbital propellant depot should be developed and the Commercial Crew Development program accelerated instead. A NASA study that was not publicly released and another from the Georgia Institute of Technology showed this option to be possibly cheaper. In 2012, the United Launch Alliance
also suggested using existing rockets with on-orbit assembly and
propellant depots as needed. The lack of competition in the SLS design
was highlighted.
In the summer of 2019, a former ULA employee claimed that Boeing,
NASA's prime contractor for SLS, viewed orbital refueling technology as a
threat to SLS and blocked further investment in it.
In 2010, SpaceX's CEO Elon Musk
claimed that his company could build a launch vehicle in the 140- to
150-tonne payload range for US$2.5 billion, or US$300 million (in 2010
dollars) per launch, not including a potential upper-stage upgrade. In the early 2010s, SpaceX went on to start development of SpaceX Starship, a planned fully reusable super-heavy launch system. Reusability is claimed to allow the lowest-cost super-heavy launcher ever made.
If the price per launch and payload capabilities for the Starship are
anywhere near Musk's claimed capabilities, the rocket will be
substantially cheaper than the SLS.
In 2011, Rep. Tom McClintock and other groups called on the Government Accountability Office (GAO) to investigate possible violations of the Competition in Contracting Act (CICA), arguing that Congressional mandates forcing NASA to use Space Shuttle components for SLS are de facto non-competitive, single source requirements assuring contracts to existing Shuttle suppliers. The Competitive Space Task Force, in September 2011, said that the new
government launcher directly violates NASA's charter, the Space Act, and
the 1998 Commercial Space Act requirements for NASA to pursue the
"fullest possible engagement of commercial providers" and to "seek and
encourage, to the maximum extent possible, the fullest commercial use of
space". Opponents of the heavy launch vehicle have critically used the name "Senate launch system",
a name that was still being used by opponents to criticize the program
in 2021, as "the NASA Inspector General said the total cost of the
rocket would reach $27 billion through 2025."
In 2013, Chris Kraft, the NASA mission control leader from the Apollo era, expressed his criticism of the system as well. Lori Garver, former NASA Deputy Administrator, has called for canceling the launch vehicle alongside the Mars 2020 rover. Phil Plait has voiced his criticism of SLS in light of ongoing budget tradeoffs between the Commercial Crew Development and SLS budgets, also referring to earlier critiques by Garver.
In 2019, the Government Accountability Office
found that NASA had awarded Boeing over US$200 million for service with
ratings of good to excellent despite cost overruns and delays. As of
2019, the maiden launch of SLS was expected in 2021. NASA continued to expect that the first orbital launch would be in 2021 as late as May 2020.
On 1 May 2020, NASA awarded a US$1.79 billion contract extension for the manufacture of 18 additional RS-25 engines. Ars Technica,
in an article published on the same day, highlighted that over the
entire RS-25 contract the price of each engine works out to US$146
million and that the total price for the four expendable engines used in
each SLS launch will be more than US$580 million. They critically
commented that for the cost of just one engine, six more powerful RD-180 engines could be purchased, or nearly an entire Falcon Heavy launch with two thirds of the SLS lift capacity.
Former NASA Administrator Charlie Bolden,
who oversaw the initial design and development of the SLS, also voiced
his criticism of the program in an interview with Politico in September
2020. Bolden said that the "SLS will go away because at some point
commercial entities are going to catch up". Bolden further stated
"commercial entities are really going to build a heavy-lift launch
vehicle sort of like SLS that they will be able to fly for a much
cheaper price than NASA can do SLS".
John Zeller, Trevor Waddell, Kyle Sullivan, Nick Saab, Evan Schurr
Parent organization
Space Advocates
Penny4NASA is a campaign run by the Space Advocates nonprofit,
a nonpartisan organization seeking to promote the expansion of funding
for the economic, scientific and cultural value of the United States'
national space program by advocating an increase in the budget for the National Aeronautics and Space Administration
to at least one percent of the United States Federal Budget. Penny4NASA
also attempts to promote public awareness of the NASA mission and
budget, and has produced a series of outreach videos, as well as
performing educational outreach via social media.
Overview
Penny4NASA is a campaign of Space Advocates, an initiative founded by John Zeller in 2012, and proposes an increase in the budget for the National Aeronautics and Space Administration to promote the scientific and technological goals of the space agency. The organization works to accomplish these aims through public outreach, educational materials, and has organized petitions to the Executive and Legislative branches of the United States government toward those aims. Penny4NASA is the campaign Space Advocates is best known for.
The Penny4NASA campaign was founded in 2012 following the testimony of astrophysicist Neil DeGrasse Tyson – curator of the Hayden Planetarium in New York – before the United States Senate Science Committee.
According to Tyson's testimony, “Right now, NASA’s annual budget is
half a penny on your tax dollar. For twice that—a penny on a dollar—we
can transform the country from a sullen, dispirited nation, weary of
economic struggle, to one where it has reclaimed its 20th century
birthright to dream of tomorrow.”
Objectives
The
Penny4NASA mission statement declares that a main goal of the campaign
is to call upon the White House and U.S. Congress "to increase NASA's
funding from its current level of 0.48% to a whole one percent of the US
annual budget."
The organization hopes to meet this aim by encouraging to public to
"consistently and in large numbers, [contact] members of congress to
tell them what [the public] want[s]."
Another goal of the Penny4NASA campaign, as part of its larger
goal to influence the public in favor of increasing the funding allotted
the U.S. space program, is to communicate accurate information about
how much funding has been allotted NASA over its operational history.
The mission statement states that "2012 is the 2nd lowest year of NASA
funding by percentage of the US budget since 1958 and 1959, their
founding years."
Neil deGrasse Tyson, a stated influence of the Penny4NASA organization,
has argued that NASA is not only underfunded, but that the general
public overestimates how much revenue is allocated to the space program.
At a March 2010 talk delivered in the University at Buffalo's Distinguished Speaker series, Tyson stated:
"By
the way, how much does NASA cost? It's a half a penny on the dollar.
Did you know that? The people are saying, 'Why are we spending money
[…].' I ask them, 'How much do you think we're spending?' They say 'five
cents, ten cents on a dollar.' It's a half a penny."
Tyson has proposed increasing the budget of NASA and suggested that
doing so would increase the capabilities of human spaceflight, allowing
the space program to "do it all," referring to pursuing multiple avenues
of exploration.
Media coverage and reception
In March 2012, Neil deGrasse Tyson was interviewed by Joshua Topolsky.
Speaking of the Penny4NASA campaign and social media initiatives, Tyson
said he was surprised by the online mobilization within 10 days of his
Senate committee testimony, and that he was "happy to learn that" people
were moved by it.
On June 10, 2012 John Zeller, then an undergraduate student at Oregon State University majoring in Computer Science, was interviewed in the Science for the People podcast.
Zeller started the Penny4NASA.org web site after observing Neil
deGrasse Tyson giving a testimony before the U.S. Senate committee on
Commerce, Science, and Transportation. Zeller states, "After watching
this video, I went on Twitter and Facebook and I saw hashtag Penny4NASA
all over the place. There had been a video put on YouTube that had
hashtag Penny4NASA all over it that was trending around 300,000 views."
The success of the video prompted Zeller to begin the web site and set
up a petition and social media around the 'Penny4NASA' hashtag that had
come to summarize the proposal of its movement.
A September 2, 2012 episode of Astronomy Cast recorded at DragonCon in Atlanta, Georgia focused on funding issues related to space exploration. Discussing the Penny4NASA proposal and supportive of its goals, astronomer Pamela Gay
stated that it may not be a realistic goal to "convince the Congress to
take a penny of every tax dollar and give it to NASA," but went on to
say it may be possible to produce "the same ultimate effect by
individuals who have the extra ten dollars and care about science and
finding that science project that they believe in and giving it ten
dollars."
Campaign efforts
In 2012, Penny4NASA organization released a two-part video series titled "We Stopped Dreaming"
to make a case for expanding the combined efforts of the National
Aeronautics and Space Administration, international space partnerships,
private space exploration and combinations thereof. Two additional videos by Brandon Fibbs were subsequently released in 2012, "Dare Mighty Things: Curiosity on Mars" and "Audacious Visions."
A petition was created in March 2012 on behalf of Penny4NASA using the U.S. White House's We the People petitioning system.
The petition argued for a reallocation of funding, stating that the
investment would be smaller than recent government expenditures,
including the Troubled Asset Relief Program during the financial crisis of 2007–2008. The White House issued an official response to the initial petition, entitled Doubling and Tripling What We Can Accomplish in Space,
stating "NASA and space are so important to our future that we do need
to be doubling and tripling what we can accomplish in this domain."
The White House's response also emphasized fiscal challenges but argued
that through effective spending to deliver results, "NASA is as strong
as ever."
On August 9, 2012, Penny4NASA published a response in an open
letter to White House Office of Science and Technology Policy Director
John Holdren, acknowledging fiscal challenges, but adding that they were
"concerned that the message of [the] organization and the almost 30,000
individuals who have signed the petition is being overlooked."
As of January 2013, the petition was taken down from the We the People website for not meeting the signature threshold.
Following the White House petition, the Penny4NASA organization
endorsed a congressional petition using the POPVOX widget, an online
tool for communicating support or dissent for particular bills on behalf
of its user base to the members of the United States Congress in a
public forum.
