SpaceX launches Europa Clipper mission cheaply

After years of speculation, NASA officially announced on Friday that SpaceX’s Falcon Heavy will launch what is arguably the most significant solar system exploration mission of the space agency, the Europa Clipper, of the 2020s.

Scheduled to launch in October 2024, the $ 4.25 billion mission will spend much of the remainder of this decade flying towards the Jovian system before entering an elongated orbit around Jupiter. The spacecraft will then make up to 44 flyovers of Europe, the intriguing Jovian ice-encrusted moon that scientists say is home to a vast ocean below the surface. It is possible that aquatic life exists there.

The total amount of the contract awarded for launch services is approximately $ 178 million, NASA said in a press release. This is an important time for SpaceX, as the company will be given one of NASA’s highest priority exploration missions. The deal also saves NASA around $ 2 billion.

The choice of a launcher for this ambitious mission was the subject of a long political process. Originally, at the request of Congress, NASA planned to launch the spacecraft on its Space Launch System rocket. There were two reasons for this. Lawmakers (especially US Senator Richard Shelby, R-Ala.) Wanted to find additional missions for the SLS rocket. And second, the powerful SLS rocket had the ability to get the Clipper to Jupiter in about four years.

However, many in the scientific community preferred to jump on SpaceX’s Falcon Heavy for various reasons. On the one hand, SpaceX offered launch services at a very low price compared to the SLS rocket, which the White House says would cost more than $ 2 billion for the Clipper mission. Scientists were also concerned that the oft-delayed SLS rocket was simply not ready for a 2024 launch date, and its selection would delay the science mission.

However, politicians continued to insist that NASA launch Clipper on the SLS rocket. Three different events ultimately forced lawmakers to give in. First, at the end of 2018, NASA scientists concluded that the Falcon Heavy could complete the Clipper mission without needing gravitational assistance from Venus, and therefore would not have to enter the solar system. internal. The Falcon Heavy could do this with the addition of a Star 48 ‘start-up stage’. (The United Launch Alliance’s Delta IV Heavy rocket would have required a flyover of Venus, greatly increasing the thermal shielding required on the Clipper spacecraft, which was ultimately ruled out.)

“Nobody is saying we’re not going on SLS,” NASA’s Barry Goldstein said at a meeting in November 2018. “But if by any chance we don’t, we don’t have the internal solar system challenge. It was a major development. It was a big problem for us. “

Second, after finalizing the plans for the Artemis Moon program, NASA realized that the main contractor for the main stage of the SLS rocket, Boeing, was simply not up to the task of building a extra rocket for the Clipper mission in time. All major SLS milestones would be needed to support efforts to land humans on the moon in the mid-2020s, according to NASA officials.

Finally, what forced Shelby and the rest of Congress to give in was a “shake” issue with the SLS rocket. This large vehicle is powered by two very large powder thrusters which produce significant vibrations. SLS program officials had told agency management that the torsional load – essentially a measure of torsion and vibration – was a certain value. However, after NASA performed wind tunnel tests, the actual value of the torsional load was almost double the estimates from the SLS program.

Adapting to that launch stress, NASA officials told Ars, would have required an additional $ 1 billion in modifications to make the spacecraft more robust. This additional cost ultimately led to NASA being able to make the Friday announcement.

List image by Trevor Mahlmann