Sojourner

This article is about the spacecraft. For the mission, see Sojourner 1 mission. For other uses, see Sojourner (disambiguation).

Sojourner was a class of spacecraft designed for interplanetary space travel, built by NASA for their crewed missions to Mars in the mid 1990s. The first ship, Sojourner 1, was launched in 1994 for its mission to land the first humans on the red planet, in competition with Roscosmos' Mars-94 spacecraft and the ship of the private competitor Helios Aerospace, Phoenix, in the race to Mars.

History[]

Design & construction[]

Sojourner lands and takes off using thrusters mounted on the belly next to the landing gear, but accelerates towards the destination with horizontal thrusters on the back. The main K-32 NERVA uses nuclear fission for power, but the craft also employs the use of large solar sails that allow for constant acceleration.^[1] ^[2]

The spacecraft was assembled and tested on the Moon near the Jamestown base, where NASA installed several facilities, including a rocket testing site. Components were brought there using the Sea Dragon rocket.^[3]

Later models[]

By March 1995, NASA had started working on the successor, Sojourner 2.^[4] The later model, Sojourner 3, held the speed record for Earth-Mars, until Helios' Unity spacecraft took that title in 1999.^[5]

Missions[]

Sojourner 1[]

Main article: Sojourner 1 mission

The first mission was initially planned for the launch window in 1996, but had to be moved up to fall 1994 after the private company Helios Aerospace announced their participation in the race to Mars and their planned launch date. Sojourner 1 launched from the Moon within 2 weeks of the other competitors. Mission commander was Danielle Poole, crew included NASA astronauts Sylvie Kaplan, Kelly Baldwin, William Tyler, and former Soviet cosmonaut Rolan Baranov, as well as Scotsman Clarke Halladay from ESA. Unfortunately, Kaplan and Halladay died during a rescue mission halfway to Mars.

Sojourner 1 landed in the canyon Melas Chasma in the Valles Marineris system in February 1995. However, due to bad visibility from a dust storm on the planet, and damages from the rescue mission earlier, the spacecraft landed hard and got its engines damaged, making it impossible to ever launch again.^[6]

By 2003, Sojourner 1 was still on Mars and was spotted by Helios worker Rich Waters as he and other Helios workers approached Happy Valley in the Hopper.^[7]

Sojourner 2[]

Sojourner 2 was the second mission with a Sojourner type spacecraft. Launched around end of 1996, it's main duty was to bring back all the astronauts stranded on Mars from the 1994 missions. The crew consisted of the astronauts Hatva, Mendoza, Kasimova and Friedman.^[8]