Peregrine Mission One

Peregrine Lunar Lander flight 01, commonly referred to as Peregrine Mission One, was an unsuccessful American lunar lander mission. The lander, dubbed Peregrine, was built by Astrobotic Technology and carried payloads for the NASA Commercial Lunar Payload Services (CLPS) program. Peregrine Mission One launched on 8 January 2024, at 2:18 am EST, on the maiden flight of the Vulcan Centaur (Vulcan) rocket. The goal was to land the first U.S.-built lunar lander on the Moon since the crewed Apollo Lunar Module on Apollo 17 in 1972.

The lander carried multiple payloads, with a payload capacity of 90 kg. Shortly after the lander separated from the Vulcan rocket in lunar injection orbit, a propellant leak developed that prevented the lander from completing its mission. After six days in orbit, the spacecraft was redirected into Earth's atmosphere, where it burned up over the Pacific Ocean on 18 January 2024.

History
In July 2017, Astrobotic announced an agreement with United Launch Alliance (ULA) to launch their Peregrine lander aboard a Vulcan launch vehicle. This first lunar lander mission, called Mission One, was initially to be launched in July 2021.

On 29 November 2018, Astrobotic was made eligible to bid on NASAs Commercial Lunar Payload Services (CLPS) to deliver science and technology payloads to the Moon.

In May 2019, Mission One received its first lander contract from NASA for 14 payloads. It also had 14 commercial payloads, including small rovers from Hakuto, Team AngelicvM, and a larger rover from Carnegie Mellon University, named Andy, which has a mass of 33 kg and is 103 cm tall. Another small rover, Spacebit, weighing 1.5 kg, was designed to travel at least 10 m on four legs. Other payloads include a library, in microprint on nickel, with Wikipedia contents and Long Now Foundation's Rosetta Project. Space burial companies Elysium Space and Celestis paid Astrobotic to carry human remains. The decision to include human remains was criticized by the Navajo Nation, whose president, Buu Nygren, argued that the Moon is sacred to the Navajo and other American Indian nations.

In June 2021, ULA CEO Tory Bruno announced that payload and engine-testing problems would delay the maiden flight of Vulcan, with Mission One aboard, to 2022. On 23 February 2023, ULA announced an expected launch date for the mission of 4 May 2023. After an anomaly during testing of the Vulcan Centaur on 29 March, the launch was delayed until June or July, and then until late 2023.

In early December 2023, Bruno said problems found during a wet dress rehearsal of the rocket would likely delay the launch until the next launch window, on 8 January.

Peregrine carries a maximum payload mass of 90 kg during Mission One, and it was planned to land on Gruithuisen Gamma.

The payload mass for the planned second mission (Mission Two) is capped at 175 kg, and the Mission Three and later missions would carry the full payload capacity of 265 kg.

Lander
In 2016, Astrobotic announced plans to build the Peregrine lander, based on their previous concept lander, Griffin, which was larger but with the same payload capacity. Astrobotic hired Airbus Defence and Space to help refine the lander's design.

The Peregrine bus is largely of aluminum alloy, and it is reconfigurable for specific missions. Its propulsion system has five thrusters built by Frontier Aerospace, each producing 150 lb (667 N) thrust. This propulsion system was designed to handle the trans-lunar injection, trajectory corrections, lunar orbit insertion, and powered descent. The propulsion system can deliver an orbiter to the Moon and perform a powered soft landing. The lander can carry up to 450 kg of bi-propellant mass in four tanks; its composition is MON-25/MMH, a hypergolic bi-propellant. For attitude control (orientation), the spacecraft uses 12 thrusters (45 N each) also powered by MON-25/MMH.

The spacecraft's avionics incorporate guidance and navigation to the Moon, and a Doppler LiDAR to assist the automated landing on four legs. From Mission 2, its landing ellipse will be 100 m x 100 m, down from 24 km × 6 km previously.

Peregrine is about 2.5 m wide and 1.9 m tall, and would have been able to deliver up to 265 kg of payload to the surface of the Moon.

Its electrical systems are powered by a lithium-ion battery that is recharged by a solar panel made of GaInP/GaAs/Ge. Radiators and thermal insulators are used to dispose of excess heat, but the lander does not carry heaters, so the first few Peregrine landers are not expected to survive the lunar night, which lasts 14 Earth days. Future missions could be adapted to do so.

For communications to Earth, the lander uses frequencies within the X-band range for uplink as well as downlink. After landing, a 2.4 GHz Wi-Fi modem is to enable wireless communication between the lander and deployed rovers on the lunar surface.

Lunar rovers
Instruments

Launch and trajectory
On 8 January 2024 ULA used the inaugural flight of the Vulcan Centaur rocket to launch the Peregrine mission. Lift-off from Cape Canaveral Space Launch Complex 41 took place at 2:18 am EST. The rocket was launched in the VC2S configuration, with two solid rocket boosters and a standard-length fairing. The solid rocket boosters separated from the vehicle at T+1 minute 50 seconds. The first stage continued firing its BE-4 engines until T+4:59 and separated a few seconds later. The Centaur upper stage started its first burn at T+5:15, which took more than 10 minutes to complete and put the vehicle into a low Earth orbit. Following a coast phase, the Centaur fired for the second time at T+43:35 to start the trans-lunar injection burn, which lasted about three minutes. The Peregrine lander separated from the rocket at T+50:26.

Peregrine was to take a 46-day trajectory to the Moon, performing burns to enter lunar orbit and slowly approach the lunar surface. Landing was planned for 23 February 2024.

Propellant leak
Roughly seven hours after the launch, Astrobotic reported that a problem, likely with the propulsion system, had "prevented [the lander] from achieving a stable sun-pointing orientation". The company conducted an unplanned maneuver of the spacecraft to turn the solar panels toward the Sun, and, after an expected communications blackout, confirmed that the spacecraft was once again generating sufficient power. However, the problem was identified as a gradual propellant leak that required constant consumption of fuel to counteract. At 21:16 EST, Astrobotic said in a statement that thrusters were operating "well beyond their expected service life cycles" and that the "spacecraft could continue in a stable sun-pointing state for approximately 40 more hours" before it would run out of fuel, then lose attitude control and power.

Later, the company confirmed that Peregrine could no longer land on the Moon, although it could continue to operate as a spacecraft. Photographs taken by the spacecraft showed damage to external insulation, perhaps caused by a valve that failed to fully close, causing the oxidizer tank to rupture.

Four days into the mission, the propellant leak appeared to slow, and Astrobotic reported that "there is growing optimism that Peregrine could survive much longer" than was previously anticipated.

Reentry
The spacecraft eventually reached a position that would have allowed it to reach the Moon with trajectory corrections. Six days into the mission, Astrobotic decided to direct the spacecraft to burn up in Earth's atmosphere to avoid space debris. In the end, the spacecraft never left the (highly elliptical) Earth orbit that the carrier rocket injected it into (except to make a controlled re-entry into Earth's atmosphere).

A controlled re-entry took place at 15:59 on 18 January EST (20:59 UTC), with possible impact somewhere near Point Nemo, a spacecraft cemetery in the South Pacific. The last contact with the spacecraft was achieved by DSS36, an antenna of the DSN in Canberra.

Future
Peregrine was the first of NASA's CLPS missions, with the second, Intuitive Machines' Odysseus, which launched and landed on the moon in February 2024. Astrobotic will have a second landing attempt, consisting of the larger Griffin lander, with launch previously scheduled for November 2024.