The billionaire space race is the rivalry among entrepreneurs who have entered the space industry from other industries - particularly computing. This private spaceflight
race involves sending privately developed rockets and vehicles to
various destinations in space, often in response to government programs
or to develop the space tourism sector.
Today, the billionaire space race is primarily between three billionaires and their respective firms:
Jeff Bezos's Blue Origin, which is seeking to establish an industrial base in space.
Prior to his death in 2018, Paul Allen was also a major player in the billionaire space race through the aerospace division of his firm Vulcan and his financing of programs such as Scaled Composites Tier One. Allen sought to reduce the cost of launching payloads into orbit.
Background
The groundwork for the billionaire space race and private spaceflight was arguably laid by Peter Diamandis, an American entrepreneur. In the 1980s, he founded an American national student space society, the Students for the Exploration and Development of Space (SEDS). Later, Jeff Bezos
became a chapter president of SEDS. In the 1990s, Diamandis,
disappointed with the state of space development, decided to spur it on
and spark the suborbital space tourism market, by initiating a prize,
the X Prize. This led to Paul Allen becoming involved in the competition, creating the Scaled Composites Tier One platform of SpaceShipOne and White Knight One which won the Ansari X-Prize in 2004. The technology of the winning entrant was then licensed by Richard Branson's Virgin Group as a basis to found Virgin Galactic. The base techniques of Tier One also form the basis for Stratolaunch Systems (formerly of Vulcan Aerospace).
Elon Musk's SpaceX was established in 2002, last among the three main
rivals. Elon Musk has expressed excitement for a new space race.
Government programs have also fuelled the billionaire space race. NASA programs such as the Commercial Crew Program (created in 2010, with grants mostly won by SpaceX and partially by Blue Origin) and the Artemis HLS
program (awarded to SpaceX in 2021 and also to Blue Origin in 2023)
have pushed the billionaires to compete against each other to be
selected for those multi-billion dollar procurement programs. The
competition has also resulted in court battles such as Blue Origin v. United States & SpaceX. Those government programs have provided critical funding for the new private space industry and its development.
30 May 2020 – SpaceX successfully launches a Falcon 9 rocket carrying the Crew Dragon space capsule during the Demo-2 mission, marking the first privately-developed crewed mission to orbit and to visit the ISS.
11 July 2021 – Richard Branson made a successful sub-orbital spaceflight as member of the Virgin Galactic Unity 22.
20 July 2021 – Jeff Bezos also made a successful sub-orbital spaceflight aboard Blue Origin's NS-16, becoming the first billionaire space company founder to cross the Karman Line.
16 September 2021 – SpaceX operates the Inspiration4 mission, the first orbital spaceflight with only private citizens aboard.
Rivalries
SpaceX vs. Blue Origin
SpaceX and Blue Origin have had a long history of conflict. Blue Origin and SpaceX have had dueling press releases that compete with each other's announcements and events.
SpaceX and Blue Origin battled for the right to lease LC-39A,
the rocket launch platform that was used to launch the Apollo Moon
missions. SpaceX won the lease in 2013, but Blue Origin filed suit in
court against that. It is currently in the hands of SpaceX, while Blue
Origin rented SLC-36 instead.
SpaceX filed suit against Blue Origin to invalidate their patent
on landing rockets aboard ships at sea. They won their court fight in
2014. SpaceX had been attempting to land rockets at sea since 2014,
finally succeeding in 2016, before Blue Origin ever even built a
sea-going platform to land rockets onto.
SpaceX and Blue Origin got into a Twitter battle about the
meaning of a used rocket, landed rocket, spacerocket, at the end of
2015, when New Shepard successfully landed, after a suborbital jaunt into space. SpaceX had previously launched and landed its Grasshopper rocket multiple times without reaching space. Then SpaceX landed a Falcon 9
first stage, which had been used to launch a satellite into orbit,
prompting more Twitter battles at the start of 2016, such as Bezos
tweeting "welcome to the club".
In late 2016, Blue Origin announced the New Glenn, directly competing against SpaceX's Falcon Heavy, with a larger rocket but lower payload.
In April 2021, SpaceX beat Blue Origin to a 2.9 billion dollar contract to build the lunar lander for NASA's Artemis program. In August 2021, Blue Origin subsequently began a legal case against NASA and SpaceX in the Court of Federal Claims, which was dismissed in November of the same year. About two years later in May 2023 NASA
awarded Blue Origin a $3.4 billion contract to develop a competing moon
lander, noting that "adding another human landing system partner to
NASA’s Artemis program will increase competition, reduce costs to
taxpayers, support a regular cadence of lunar landings, further invest
in the lunar economy, and help NASA achieve its goals on and around the
Moon in preparation for future astronaut missions to Mars."
Blue Origin vs. Virgin Galactic
Blue Origin and Virgin Galactic are in the same market, suborbitalspace tourism, with the space capsuleNew Shepard and the spaceplaneSpaceShipTwo, respectively.
The two systems made their first flights with multiple passengers
within 10 days: SpaceShipTwo flew on July 11, 2021 and New Shepard
followed on July 20, both carrying their billionaire founders and a few
other passengers. As of July 2023, SpaceShipTwo has made three tourism
flights with two pilots and four passengers each while New Shepard has
made six flights with six passengers each.
Former rivalries
Stratolaunch vs. Virgin Orbit
The
Stratolaunch rivalries are no longer part of the billionaire space
race, after 2019, having been suspended at the time of Paul Allen's
death.
The Stratolaunch company has since continued operations under new
ownership, but does not focus on orbital space launches anymore.
Vulcan Aerospace subsidiary Stratolaunch Systems planned to air-launch satellite launcher rockets, the same profile as planned by Virgin Orbit for its LauncherOne operations. While LauncherOne was developed and launch aircraft procured (once White Knight Two, now 747 Cosmic Girl), the Scaled Composites "Roc" Model 351
is still being developed (as of 2022) and the rocket to mate to it (the
company has refocused away from orbital spaceflight) has yet to be
selected. After the death of Paul Allen in 2018, Stratolaunch was sold off, and no longer a billionaire insurgent venture.
Starship HLS, or Starship Human Landing System, is a lunar lander variant of the Starship spacecraft that is slated to transfer astronauts from a lunar orbit to the surface of the Moon and back. It is being designed and built by SpaceX under the Human Landing System contract to NASA as a critical element of NASA's Artemis program to land a crew on the Moon no earlier than 2026.
The mission plan calls for a Super Heavy booster to launch a Starship HLS into an Earth orbit, where it will be refueled by multiple Starship tanker spacecraft before boosting itself into a lunar near-rectilinear halo orbit (NRHO). There, it will rendezvous with a crewed Orion spacecraft that will be launched from Earth by a NASA Space Launch System
(SLS) launcher. A crew of two astronauts will transfer from Orion to
HLS, which will then descend to the lunar surface for a stay of
approximately 7 days which is to include five or more EVAs. It will then return the crew to Orion in NRHO.
In the third phase of its HLS procurement process NASA awarded
SpaceX a contract in April 2021 to develop, produce, and demonstrate
Starship HLS. An uncrewed test flight is planned for 2024 to demonstrate
a successful landing on the Moon. Following that test, a crewed flight
is expected to occur as part of the Artemis 3 mission, no earlier than December 2025. NASA later contracted for an upgraded version of Starship HLS to be used on the Artemis 4 mission.
Design
Starship HLS is a variant of SpaceX's Starship spacecraft
optimized to operate on and around the Moon. In contrast to the
Starship spacecraft from which it derives, Starship HLS will never
reenter an atmosphere, so it does not have a heat shield or flight control surfaces. This makes it much lighter than a regular Starship, so Elon Musk
has tweeted that it may only take 4 (rather than 8 for the normal
version) tanker Starship launches to refuel a Starship HLS to the point
where it has enough fuel for a lunar landing.
In contrast to other HLS designs that proposed multiple stages, the
entire spacecraft will land on the Moon and will then launch from the
Moon. Like other Starship variants, Starship HLS has six Raptor
engines mounted at the tail which are used when the Starship HLS acts
as the second stage during the launch from Earth. They are also used as
its primary propulsion system in all other flight phases. Within 100
meters of the lunar surface, the variant will utilize high‑thrust RCS thrusters located mid‑body to avoid plume impingement problems with the lunar regolith. The thrusters burn gaseous oxygen and methane instead of the liquid oxygen and methane used by the Raptors. However, these thrusters may not be needed. Starship HLS is supplied with electrical power by a band of solar panels around the circumference of the vehicle.
Starship HLS requires in-orbit propellant transfer
in its mission profile. Prior to the launch of the HLS vehicle from
Earth, a Starship variant configured as a propellant depot would be
launched into an Earth orbit and then partially or fully filled by between four and fourteen Starship tanker flights carrying propellant. The Starship HLS vehicle would then launch and rendezvous with the already-loaded propellant depot and refuel before transiting from Earth orbit to Lunar orbit.
Starship HLS incorporates the following design characteristics:
support for a greater number of EVAs on the lunar surface than the minimum required by NASA in the 2020 solicitation
excess-propellant margin can be applied to expedite an emergency ascent from the Moon
Within the Artemis lunar landing architecture as of April 2021, a NASA Orion spacecraft is planned to be launched by a Space Launch System rocket and rendezvous with a waiting Starship HLS lander in a near-rectilinear halo orbit
around the Moon. The crew of Orion would then dock with, and transfer
to Starship HLS, which would subsequently depart and descend to the
lunar surface. After lunar surface operations, Starship HLS will
lift-off from the Moon and return to lunar orbit to rendezvous with
Orion. The crew then transfers back to Orion and departs for Earth.
Although not confirmed yet, Starship HLS could, in theory, be refueled
in orbit to carry more crews and cargo to the surface.
History
Starship HLS builds on the SpaceX Starship
system by adding a new spacecraft variant called Starship HLS. This
spacecraft will be used in conjunction with the Starship booster (called
Super Heavy)
and two additional Starship spacecraft variants, "tanker" and "depot",
that were already being planned prior to the HLS contract.
The SpaceXStarship concept was initially conceived in the early 2010s as a spacecraft that would be principally built for the Mars colonization effort that SpaceX CEOElon Musk has advocated since 2011, with the first colonists arriving no earlier than the middle of the 2020s.
By 2016, the scope became somewhat broader, when Musk realized
the high-level design SpaceX had been working on for the Starship
vehicle allowed for variants that would be suitable for interplanetary travel more generally, and could work both on planets with and without an atmosphere.
Lunar destination flights, however, were not generally emphasized by
Musk, and he specifically stated that the Moon was not a necessary step
on the path to Mars.
By late 2018, SpaceX had specified the primary construction material for Starship to be stainless steel – after approximately a year of building manufacturing pathfinder hardware out of carbon composite materials—and manufacture of the initial test article including pressure vessel construction for the liquid methane and liquid oxygen tanks began in early 2019.
Starship
itself has been in privately-funded development by SpaceX since the
mid-2010s, but the HLS (Human Landing System) variant is being developed
under contracts with the United States' National Aeronautics and Space Administration
(NASA). The initial contracted design work started in May 2020, with
selection and funding for full-development occurring in April 2021, when
Starship HLS was selected by NASA to land "the first woman and the next
man" on the Moon during the Artemis 3 mission, potentially as early as 2024.
NASA signed a US$2.89 billion contract with SpaceX to develop and manufacture Starship HLS, and to conduct two flights – an uncrewed demonstration mission, and a crewed lunar landing. Starship HLS is intended to dock in a lunar NRHO with either the NASA Orion spacecraft or NASA lunar Gatewayspace station, in order to take on passengers before descending to the lunar surface and return them after ascent.
Starship HLS, with HLS being an initialism for Human Landing
System, was first made public when it was initially selected by the NASA
in April 2020 for a design study as part of their Artemis program,
which aims to land humans on the Moon. SpaceX was one of three teams
selected to develop competing lunar lander designs for the Artemis
program over a year-long period starting in May 2020. The other landers in consideration were Dynetics HLS, developed by aerospace manufacturer Dynetics, and the Integrated Lander Vehicle, developed by a team led by Blue Origin. NASA intended to later select and fund at most two of these landers to continue to perform initial demonstration flights.
On 16 April 2021, NASA selected only Starship HLS for crewed lunar lander development plus two lunar demonstration flights – one uncrewed and one crewed – no earlier than 2024. The contract is valued at US$2.89 billion over a number of years. Two NASA Artemis astronauts are to land on the first crewed Starship HLS landing.
NASA had previously stated that it preferred to fund development of
multiple Human Landing System proposals with dissimilar capabilities;
however, "only one design was selected for an initial uncrewed
demonstration and the first crewed landing, due to significant budget
constraints" for the human landing system program imposed by US Congress.
NASA stated that the unselected proposals – Dynetics HLS and Blue
Origin ILV – as well as landers from other companies would be eligible
for later lunar landing contracts.
On 26 April 2021, Blue Origin and Dynetics separately protested the award to SpaceX at the US Government Accountability Office (GAO).
On 30 July 2021, the GAO rejected the protests and found that "NASA did
not violate procurement law" in awarding the contract to SpaceX, who
bid a much lower cost and more capable human and cargo lunar landing
capability for NASA Artemis. Soon after GAO rejected the appeal, NASA made the initial $300 million contract payment to SpaceX.
The protest action delayed NASA from authorizing work on the contract,
and thus delayed the start of work by SpaceX for 95 days. Blue Origin produced infographic posters that highlight the complexity of Starship HLS, for example the fact that on orbit refuelling with cryogenic fuels
like that Starship HLS uses has never been demonstrated, while showing
its own lunar lander in a positive light by stating that it uses proven
technology.
On 13 August 2021, Blue Origin filed a lawsuit in the US Court of Federal Claims challenging "NASA's unlawful and improper evaluation of proposals". Blue Origin asked the court for an injunction to halt further spending by NASA on the existing contract with SpaceX,
and NASA stopped work on the contract on 19 August, after SpaceX had
been allowed to work on the NASA-specific parts of Starship HLS for just
three weeks since the work had been previously halted in April.
Reactions to the lawsuit were negative, with many criticizing Blue
Origin for causing unnecessary delays to the Artemis program. On 4 November, the court granted the federal government's motion to dismiss the case, and NASA announced that it would resume work with SpaceX as soon as possible.
"Option B" contract
On
23 March 2022, NASA announced it would be exercising "option B", an
option under the initial SpaceX HLS contract that would allow a
second-generation Starship HLS design to conduct a demonstration mission
after Artemis 3.
On 15 November 2022, NASA announced the Option B award of US$1.15 billion, and announced that this crewed landing is to occur as part of Artemis 4. The flight will include docking with the Gateway.
The Option B HLS will meet NASA's requirements for a "sustainable" HLS.
These include the ability to support a crew of four and longer-duration
lunar surface stays.
Subsequent contracts
After
NASA awarded the Option A contact to SpaceX, congress directed NASA to
award a second HLS contract. NASA responded by creating "Appendix P" for
a non-SpaceX sustainable HLS. This lander will be used for Artemis 5 as
its crewed demonstration flight. In May 2023, Blue Origin was awarded
$3.4 billion by NASA to develop their Blue Moon lunar lander, compared to the $2.89 billion of the original bid that had been awarded to SpaceX for Option A. NASA intends to allow Starship HLS option B and the Blue Moon lander to compete for Artemis missions after Artemis 5.
According to Eric Berger of Ars Technica,
the manufacturing process starts with rolls of steel, which are
unrolled, cut, and welded along the cut edge to create a cylinder of 9 m
(30 ft) in diameter, 1.82 m (6 ft) in height, and 4 mm (0.16 in) thick,
and around 1,600 kg (4,000 lb) in mass. These cylinders, are stacked
and welded along their edges to form the outer layer of the rocket.
Inside, the methane and oxygen tanks
are separated by robot-made domes. Before final assembly, grid fins are
added to the interstage, and the chines are added after stacking of the
propellant tanks.
Design
The first-stage Super Heavy booster is 71 m (233 ft) tall, 9 m (30 ft) wide, and is composed of four general sections: the engine section, the fuel tank, the oxygen tank, and the interstage including hot staging. Elon Musk has stated that the final design will have a dry mass
between 160 t (350,000 lb) and 200 t (440,000 lb), with the tanks
weighing 80 t (180,000 lb) and the interstage 20 t (44,000 lb).
Tanks
The fuel tank on the Super Heavy is separated by a common bulkhead, similar to the ones used on the S-II and S-IVB stages on the Saturn V rocket. The oxygen tank has four chines attached. These protect the COPVs, CO2 tanks for fire suppression, as well as providing lift during flight.
The booster's tanks were reported as holding 3,600 t
(7,900,000 lb) of propellant, consisting of 2,800 t (6,200,000 lb) of
liquid oxygen and 800 t (1,800,000 lb) of liquid methane. However, current booster prototypes can only hold 3,400 t (7,500,000 lb) of propellant.
Engines
The engine section supports the 33 raptor engines during flight. The engines are arranged in three concentric rings. The outer ring of 20 engines is of the "Raptor Boost" configuration with gimbal actuators removed to save weight and a modified injector with reduced throttle performance in exchange for greater thrust. Raptor utilizes a full-flow staged combustion cycle, which has both Oxygen and Methane rich turbopumps.
Prior to 2014, only two full-flow staged-combustion rocket engine
designs had advanced enough to undergo testing on test stands: the
Soviet RD-270 project in the 1960s and the Aerojet Rocketdyne Integrated
Powerhead Demonstrator in the mid-2000s.
At full power, all engines produce a collective 75.9 MN (17,100,000 lbf) of thrust. However, Raptor 3 is planned to bring thrust up to 90 MN (20,000,000 lbf).
Interstage
The interstage is also equipped with four electrically actuated grid fins,
each with a mass of 3 t (6,600 lb). Adjacent pairs of grid fins are
only spaced sixty degrees apart instead of being orthogonal (as is the
case on Falcon 9) to provide more authority in the pitch axis. Unlike Falcon 9, the grid fins do not retract and remain extended during ascent. During unpowered flight in the vacuum of space, control authority is provided by cold gas thrusters fed with residual ullage gas.
The interstage also has protruding hardpoints, located between grid fins, allowing the booster to be lifted or caught by the launch tower.
After the first Starship test flight,
all boosters will now have an additional 2m tall vented interstage
added, as well as a protective dome. Elon Musk has indicated this change
may gain an additional 10% payload to orbit as a result.
Mission profile
About one hour and thirty-nine minutes before flight, the super heavy
booster begins propellant load. At the T- 16:40 mark, engine chill
begins on the booster. This is to protect the engine's turbopumps from thermal shock. At eight seconds before flight, the thirty-three engines startup-sequence begins.
After liftoff, the engines burn for 169 seconds, at which point 30 of
its engines shut off, leaving only three center ones running at 50%
thrust. Then, the ship ignites its engines while still attached to the
booster and separates. The boostback burn lasts for 55 seconds. About eight minutes to flight, the engines reignite, and the booster is caught by a pair of mechanical arms.
78% of 3,600 t (7,900,000 lb) is 2,800 t (6,200,000 lb) of liquid oxygen.
The date of the first part for the booster being spotted
Boosters do not have an engine skirt. Without engines, boosters are about 3 meters shorter.
BN1
BN1 was the first Super-Heavy Booster prototype, a pathfinder that was not intended for flight tests.
Sections of the ~70 m (230 ft) tall test article were manufactured
throughout the fall. Section stacking began in December 2020. BN1 was fully stacked inside the High Bay on 18 March. On 30 March 2021, BN1 was scrapped.
BN3/B3
BN3 (Booster 3) was used for ground tests. A cryogenic proof test was completed (13 July 2021). Booster 3 completed stacking in the High Bay (29 June 2021), and moved to the test pad without engines. Three engines were subsequently added.
A static fire test was conducted 19 July 2021. BN3/Booster 3 was partially scrapped on 15 August 2021, while the LOX tank remained welded to the Test Stand. The LOX tank was taken off the Test Stand on the 13th January 2022.
B4
Booster 4 first
became visible on 3 July 2021. Musk ordered several hundred SpaceX
employees at Hawthorne to relocate to Boca Chica to accelerate the
development of SN20, BN4, and the Orbital Launch Platform in an attempt to put the Starship system on the pad by 5 August 2021. BN4 was fully stacked on 1 August, with a full complement of 29 engines installed on 2 August 2021. Grid fins were added to support atmospheric reentry testing.
SN20 was stacked on top of Booster 4 on 6 August 2021 for a fitting test, making it the largest rocket ever.
Booster 4 was then returned to the High Bay for secondary wiring. On 9
September 2021, Booster 4 came again to the launch site on top of the
Orbital Launch mount.
B4 completed its first cryogenic proof test (17 December 2021),
and a pneumatic proof test (19 December 2021). It underwent another
cryogenic proof test and a full-load cryogenic proof test. B4 and Ship
20 were then retired.
B5
Parts for B5 were observed as early as 19 July 2021. Stacking for BN5 completed in November, although on 8 December 2021, B5 retired to stand alongside SN15 and SN16.
Parts for B7 were first spotted on 29 September 2021. B7 was placed
on the orbital launch mount on 31 March 2022. After completing a
cryogenic proof test on 4 April 2022, it was placed onto the new booster
test stand on 8 April 2022. B7 completed another cryogenic test on 14
April 2022, but the downcomer suffered a failure and ruptured. On 18
April 2022, B7 returned to the production site for repairs. On 5 May
2022, B7 was again placed on the orbital launch mount. B7 then completed
two cryogenic tests on 9 and 11 May 2022. It was then returned back to
the production site and entered the new Mega Bay (also known as Wide Bay
or High Bay 2), for repairs and additional equipment, upgraded grid
fins and engines, and two more 'chines' or 'strakes' (triangular
structures placed on the aft section to aid in aerodynamic control).
B7 went through more testing (11 July 2022) where it experienced an
anomaly during an attempted 33 engine spin prime test and a detonation
occurred underneath the engines. The booster then rolled back to the Mega Bay. B7 was transported back to the orbital launch pad with 20 outer Raptor engines (August 4 to August 5, 2022)
and completed its first single engine static fire test (August 9,
2022). B7 completed a 20-second static fire (August 11, 2022), the
longest static fire on a Starship prototype to date. Following a successful set of tests, it returned to the production site to receive the remaining 13 engines. B7 was lifted back onto the launch mount using the chopsticks catching and lifting system (23 August 2022).
It underwent further testing including its 13 inner engines (26 August
2022). B7 completed a multi-engine static fire (31 August 2022). This was followed by multiple spin prime tests, and a seven-engine static fire on 19 September 2022. B7 again returned to the Mega Bay on 21 September 2022. After upgrades it was again lifted on the launch pad (8 October 2022). Ship 24 was then stacked on top B7 (12 October 2022) and was removed after completing multiple cryogenic load tests. B7 then completed a spin prime test of multiple engines, (12 November 2022) and afterwards a 14 engine static fire test, (14 November 2022) and finally an 11 engine static fire in an autogenous pressurization test (29 November 2022). On December 9, 2022, B7 rolled back to the Mega Bay
for further shielding. In January 2023, Booster 7 was rolled back to
the launch site where it was stacked with Ship 24 on the OLM for partial
and full Wet Dress Rehearsals (Jan 23)
before Ship 24 was destacked and sent to the Rocket Garden for final
TPS work. On February 9, 2023, Booster 7 attempted a 10 second duration
33-engine static fire where 31 of the 33 engines successfully fired for
the full duration. One of its engines was disabled just prior to
testing, and one engine shutdown prematurely. On April 20, 2023, it was
intentionally destroyed in the SpaceX Starship Integrated Flight Test after spinning out of control.
B8
The first part of
the booster, the engine thrust puck, was spotted on October 5, 2021.
Other parts for B8 were observed on February 3, 2022. The booster was fully stacked on July 8, 2022. It travelled to the launch site on 19 September 2022. Booster 8 was scrapped soon after in favor of Booster 9, Booster 8's HPU's were placed on Booster 7 along with other parts.
B9
The engine thrust
puck of the booster was first spotted on October 24, 2021. The vehicle
finished stacking in late 2022, and was moved to the OLS cryo station on
December 15, 2022. Two cryogenic proof tests were conducted on December
21, 2022, and December 29, 2022, both of which were successful. The
booster was rolled back to the Mega Bay on January 10, 2023. Among many
other upgrades, Booster 9 is the first to feature an electric Thrust
Vector Control (often abbreviated to ETVC) gimbaling system of the raptor engines. This system replaces the hydraulics HPU's
that were used until Booster 8. Booster 9 is currently slated to fly
with Ship 25 on the second Integrated Flight Test. On July 20, Booster 9
was rolled out to the launch site. Later, in the night of July 20 to
July 21, it was lifted onto the Orbital Launch Mount in preparation for
its testing campaign. On July 23 Booster 9 performed a cryogenic prof test on the orbital launch mount.
This was followed by a Spin Prime on August 4, 2023. On August 6, 2023,
Booster 9 fired 29 engines for 2.7 seconds, instead of the planned 33
engines for 5 seconds. It was then moved off of the Orbital Launch
Mount, and rolled back to the Mega Bay, where it's hot staging extension
was added on August 16, 2023. B9 was moved back onto the Orbital Launch Mount on August 22, 2023, and underwent another spin prime test the next day.
On August 25, 2023, Booster 9 underwent a static fire of all 33
engines, lasting around 6 seconds. Two engines shut off early during the
test.
On September 5, 2023, S25 was lifted onto B9 for the first time. On
September 14, 2023, S25 was removed from B9, followed one week later by
the Vented Interstage. On September 26, 2023, the Vented Interstage was
lifted onto B9, only to be removed on October 9, 2023.
B10 and subsequent
Not much is known about boosters 10 and 11, except that they also use booster 9's ETVC, as well as elliptical domes. B10 was fully stacked in March 2023. In June 2023, B11 was fully stacked, and B12 began assembly.
On July 19, 2023, B10 underwent a cryogenic proof test. It was later
moved to the rocket garden, and was then moved to the Mega Bay. However,
on September 10, 2023, B10 was moved back to Masseys on a Thrust
Simulator Stand. A croygenic test was performed 3 days later.
As of September 13, 2023, it is unknown whether the Thrust Simulator
was used during the test. It was moved back to the Mega Bay on September
20, 2023, presumably for engine and interstage installation. On October
12, 2023, B11 was moved to the Masseys test site on a Thrust Simulator
Stand, where it was cryo tested two days later.
Test Tank 1
(TT1) was a subscale test tank consisting of two forward bulkheads
connected by a small barrel section. TT1 was used to test new materials
and construction methods. On 10 January 2020, TT1 was filled with water
and tested to failure as part of an ambient temperature test, reaching a
pressure of 7.1 bar (103 psi).
Test Tank 2 (TT2) was another subscale test tank similar
to TT1. On 27 January 2020, TT2 underwent an ambient temperature
pressure test where it reached a pressure of 7.5 bar (109 psi) before a
leak occurred. Two days later, it underwent a cryogenic proof test to destruction, bursting at 8.5 bar (123 psi).
GSE 4.1 was first spotted in August 2021, and was the
first ground support equipment (GSE) test tank built, made from parts of
GSE 4. It underwent a cryogenic proof test (August 23) before it was
rolled to Sanchez site.
It was rolled back to the launch site in November 2021 and underwent an
apparent cryogenic proof test to failure (January 18), where it burst
at an unknown pressure.
EDOME is a test tank created to test flatter domes,
possibly used on future Starship prototypes. It was moved to the launch
site in July 2022, and back to the production site the next month, and
never received testing. It was later moved from the production site to
the new Masseys site on 22 September 2022, which conducts non-flight
hardware testing. On 30 September 2022, it burst during a cryogenic
pressure test to failure. After repairs, it was tested to destruction in
late October 2022.
Super Heavy-based test articles
BN2.1 was rolled out on 3 June 2021for cryogenic tests (8 June) and (17 June).
B2.1 (not BN2.1) survived three cryogenic tests on 1, 2, and 3 December.
B6.1 was originally intended to be the third super heavy
intended for flight, but was repurposed as a test tank. In May 2023, it
was used to test the modified FTS system, after the FTS on B7 and S24
failed to destroy the vehicle.
B7.1 was first cryogenically proof tested on 28 June 2022, and tested again on 19 July 2022. During a suspected pressurize to failure test two days later, it received minor damage.
After repairs, it underwent a fourth cryogenic proof test (27 July), a
fifth (1 September), and a sixth five days later. It then rolled back to
the production site (16 September). B7.1 left the production site (22
September) to head to the new Masseys site.
Hot Stage Load Head (HSLH) is a test article designed for verify the structural integrity of the interstage
of Super Heavy Boosters 9+. It was transported to the Massey's test
site on July 30, 2023, before being loaded onto the Can Crusher testing
device. As of August 29, 2023, it is believed to have completed testing.
A multiple independently targetable reentry vehicle (MIRV) is an exoatmosphericballistic missile payload containing several warheads, each capable of being aimed to hit a different target. The concept is almost invariably associated with intercontinental ballistic missiles carrying thermonuclear warheads,
even if not strictly being limited to them. By contrast, a unitary
warhead is a single warhead on a single missile. An intermediate case is
the multiple reentry vehicle
(MRV) missile which carries several warheads which are dispersed but
not individually aimed. Only the United States, the United Kingdom,
France, Russia and China are currently confirmed to have deployed MIRV
missile systems. Pakistan is developing MIRV missile systems. Israel is suspected to possess or be in the process of developing MIRVs.
The first true MIRV design was the Minuteman III, first successfully tested in 1968 and introduced into actual use in 1970. The Minuteman III held three smaller W62 warheads, with yields of about 170 kilotons of TNT (710 TJ) each in place of the single 1.2 megatons of TNT (5.0 PJ) W56
used in the earlier versions of this missile. From 1970 to 1975, the
United States would remove approximately 550 earlier versions of the
Minuteman ICBM in the Strategic Air Command's
(SAC) arsenal and replace them with the new Minuteman IIIs outfitted
with a MIRV payload, increasing their overall effectiveness.
The smaller power of the warhead was offset by increasing the accuracy
of the system, allowing it to attack the same hard targets as the
larger, less accurate, W56. The MMIII was introduced specifically to
address the Soviet construction of an anti-ballistic missile
(ABM) system around Moscow; MIRV allowed the US to overwhelm any
conceivable ABM system without increasing the size of their own missile
fleet. The Soviets responded by adding MIRV to their R-36
design, first with three warheads in 1975, and eventually up to ten in
later versions. While the United States phased out the use of MIRVs in
ICBMs in 2014 to comply with New START, Russia continues to develop new ICBM designs using the technology.
The introduction of MIRV led to a major change in the strategic
balance. Previously, with one warhead per missile, it was conceivable
that one could build a defense that used missiles to attack individual
warheads. Any increase in missile fleet by the enemy could be countered
by a similar increase in interceptors. With MIRV, a single new enemy
missile meant that multiple interceptors would have to be built, meaning
that it was much less expensive to increase the attack than the
defense. This cost-exchange ratio was so heavily biased towards the attacker that the concept of mutual assured destruction became the leading concept in strategic planning and ABM systems were severely limited in the 1972 Anti-Ballistic Missile Treaty in order to avoid a massive arms race.
Purpose
The military purpose of a MIRV is fourfold:
Enhance first-strike proficiency for strategic forces.
Providing greater target damage for a given thermonuclear weapon
payload. Several small and lower yield warheads cause much more target
damage area than a single warhead alone. This, in turn, reduces the
number of missiles and launch facilities required for a given
destruction level - much the same as the purpose of a cluster munition.
With single-warhead missiles, one missile must be launched for each
target. By contrast, with a MIRV warhead, the post-boost (or bus) stage
can dispense the warheads against multiple targets across a broad area.
Reduces the effectiveness of an anti-ballistic missile system that relies on intercepting individual warheads.
While a MIRV attacking missile can have multiple warheads (3-12 on
United States and Russian missiles, or 14 in a maximum payload
shorter-range configuration of the Trident II now barred by
START), interceptors may have only one warhead per missile. Thus, in
both a military and an economic sense, MIRVs render ABM systems less
effective, as the costs of maintaining a workable defense against MIRVs
would greatly increase, requiring multiple defensive missiles for each
offensive one. Decoy re-entry
vehicles can be used alongside actual warheads to minimize the chances
of the actual warheads being intercepted before they reach their
targets. A system that destroys the missile earlier in its trajectory
(before MIRV separation) is not affected by this but is more difficult,
and thus more expensive to implement.
MIRV land-based ICBMs were considered destabilizing because they tended to put a premium on striking first. The world's first MIRV—US Minuteman III
missile of 1970—threatened to rapidly increase the US's deployable
nuclear arsenal and thus the possibility that it would have enough bombs
to destroy virtually all of the Soviet Union's nuclear weapons and negate any significant retaliation. Later on the US feared the Soviet's MIRVs because Soviet missiles had a greater throw-weight
and could thus put more warheads on each missile than the US could. For
example, the US MIRVs might have increased their warhead per missile
count by a factor of 6 while the Soviets increased theirs by a factor of
10. Furthermore, the US had a much smaller proportion of its nuclear
arsenal in ICBMs than the Soviets. Bombers could not be outfitted with
MIRVs so their capacity would not be multiplied. Thus the US did not
seem to have as much potential for MIRV usage as the Soviets. However,
the US had a larger number of submarine-launched ballistic missiles,
which could be outfitted with MIRVs, and helped offset the ICBM
disadvantage. It is because of their first-strike capability that
land-based MIRVs were banned under the START II agreement. START II was ratified by the Russian Duma on 14 April 2000, but Russia withdrew from the treaty in 2002 after the US withdrew from the ABM treaty.
Mode of operation
In a MIRV, the main rocket motor (or booster) pushes a "bus" (see illustration) into a free-flight suborbital ballistic flight path. After the boost phase, the bus maneuvers using small on-board rocket motors and a computerized inertial guidance system.
It takes up a ballistic trajectory that will deliver a re-entry vehicle
containing a warhead to a target and then releases a warhead on that
trajectory. It then maneuvers to a different trajectory, releasing
another warhead, and repeats the process for all warheads.
The precise technical details are closely guarded military secrets, to hinder any development of enemy counter-measures. The bus's on-board propellant limits the distances between targets of individual warheads to perhaps a few hundred kilometers. Some warheads may use small hypersonicairfoils during the descent to gain additional cross-range distance. Additionally, some buses (e.g. the BritishChevaline system) can release decoys to confuse interception devices and radars, such as aluminized balloons or electronic noisemakers.
Accuracy is crucial because doubling the accuracy decreases the
needed warhead energy by a factor of four for radiation damage and by a
factor of eight for blast damage. Navigation system accuracy and the
available geophysical information limits the warhead target accuracy.
Some writers believe that government-supported geophysical mapping initiatives and ocean satellite altitude systems such as Seasat may have a covert purpose to map mass concentrations and determine local gravity anomalies, in order to improve accuracies of ballistic missiles. Accuracy is expressed as circular error probable
(CEP). This is the radius of the circle that the warhead has a 50
percent chance of falling into when aimed at the center. CEP is about
90–100 m for the Trident II and Peacekeeper missiles.
MRV
A multiple re-entry vehicle (MRV) system for a ballistic missile
deploys multiple warheads above a single aimpoint which then drift
apart, producing a cluster bomb-like effect. These warheads are not
individually targetable. The advantage of an MRV over a single warhead
is the increased effectiveness due to the greater coverage; this
increases the overall damage produced within the center of the pattern,
making it far greater than the damage possible from any single warhead
in the MRV cluster; this makes for an efficient area-attack weapon and
makes interception by anti-ballistic missiles more challenging due to the number of warheads being deployed at once.
Improved warhead designs allow smaller warheads for a given
yield, while better electronics and guidance systems allow greater
accuracy. As a result, MIRV technology has proven more attractive than
MRV for advanced nations. Multiple-warhead missiles require both a
miniaturized physics package
and a lower mass re-entry vehicle, both of which are highly advanced
technologies. As a result, single-warhead missiles are more attractive
for nations with less advanced or less productive nuclear technology.
The United States first deployed MRV warheads on the Polaris A-3SLBM in 1964 on the USS Daniel Webster. The Polaris A-3
missile carried three warheads each having an approximate yield of 200
kilotonnes of TNT (840 TJ). This system was also used by the Royal Navy
who also retained MRV with the Chevaline upgrade, though the number of warheads in Chevaline was reduced to two due to the ABM counter-measures carried. The Soviet Union deployed 3 MRVs on the R-27U SLBM and 3 MRVs on the R-36P ICBM. Refer to atmospheric re-entry for more details.