On May 21st 2018, Orbital ATK’s Antares launch vehicle orbited the companies Cygnus OA-9 cargo hauling spacecraft. Launched from the little known NASA Wallops Island in Virginia, it took off from pad 0A at 08:44 UTC. OA-9 took 3,250 kg of cargo to the international space station, along with several cubesats that with deployer hardware added roughly 120 kg. This launch was in honour of J.R.Thompson, former Orbital Science CEO, who passed away in 2017.
It was the third flight of the Antares 230 variant, a redesigned vehicle powered by two Energomash RD-181 engines instead of the AJ-26 engines that powered the first five Antares flights. The change was made after one of the AJ-26 turbopumps failed and triggered a destructive explosion above the pad in 2004. Cygnus OA-9 was the sixth enhanced Cygnus with a stretched cargo module, but only the third to fly on Antares, Atlas 5 launched the other three.#
According to Orbital ATK, Cygnus OA-9 weighed 6,173 kg at launch, matching OA-8 payload for heaviest launched by an Antares rocket. The RD-181 engines produce a total of 392 tonnes of thrust at liftoff, that powers the 293 tonne rocket into the sky. Built in Ukraine (former Soviet design), the first stage burned for 211 seconds. After first stage shutdown it seperated and coasted “up hill” for 37 seconds before the Orbital ATK Castor 30XL second stage motor ignited to produce 51 tonnes of thrust for 160 seconds. The payload fairing separated 12 seconds before second stage ignition. Cygnus separated into a 198 x 317 km x 51.63 deg orbit about 9 min 6 sec after liftoff.
At 11:05 UTC on May 5th 2018 the forth Atlas launch of the year launched the long awaited InSight mission on a course for mars. Launching from Vandenberg Air Force Base the AV-078 (the launch designation) was an Atlas V in 401 configuration. It was the first interplanetary launch from the west coast of the United States. Liftoff of the Atlas V with a 4m payload fairing was from Space Launch Complex 3 East.
The rocket had one main payload, the InSight Mission and two CubeSats. InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) is a robotic lander designed to study the interior of the planet Mars. I weighed 694 kg at launch, including a 425 kg fueled lander. The lander carries a probe that will be hammered 15m into the Mars surface, a seismometer, a magnetometer (first expected to land on the surface of Mars), a laser reflector, along with other instruments. The lander also has a robotic arm to move payloads around, but there will be another post in the future discussing the instruments in more detail. The two CubeSats on board are known as MarCO-A and MarCO-B, each weighing about 13.5 kg. They will fly by Mars while conducting a data relay experiment with InSight.
The design of InSight was developed from the 2008 Phoenix Mars Lander. The previous lander was launched on Delta 2 rockets compared to the Atlas V, both built and launched by the United Launch Alliance. The Atlas V does have excess capability for the mission (slightly overkill) but this allowed it to be launched from Vandenberg AFB. Previous solar orbit missions (like this one) were launched from the Cape to gain the site’s eastward earth rotational velocity. Vandenberg launches have to fly south or westerly direction across the Pacific Ocean. InSight was originally planned to launch in 2016 but was delayed to 2018 due to the main instrument failing.
AV-078 started on a 158 degree azimuth, aiming towards a 63.4 degree Low Earth Parking Orbit. The LOX/RP-1 fueled RD-180 powered first stage fired for 4 minutes and 4 seconds. The Centaur’s RL10C-1 LOX/LH2 engine then fired for 8 minutes and 48 seconds to reach the parking orbit. It then coasted for 65 minutes and 40 seconds then performing a second, 5 minute and 23 second burn to accelerate into a trans-Mars solar orbit. Insight separated 9 minutes after at about T+1 hour, 33 minutes and 19 seconds. The CubeSats separated shortly after.