A SpaceX Falcon 9 rocket carrying NASA’s tiny IXPE X-ray telescope was last deployed to Pad 39A at Kennedy Space Center (KSC) ahead of a launch scheduled for Thursday, December 9.
The Falcon 9 is expected to take off at the beginning of a 90-minute window that opens at 1:00 am EST (06:00 UTC). The only payload: a unique 330 kg (~ 730 lb) spacecraft known as the Imaging X-ray Polarimetry Explorer (IXPE) hoping to analyze the polarization of X-rays to explore mysterious, nebulous, black holes. dead, beacon-like stars called pulsars in unprecedented detail. The mission is also interesting for the simple disparity between the size of the payload and the rocket that will launch it.
As stated, IXPE will weigh about a third of a ton at launch. Meanwhile, SpaceX’s Falcon 9 will weigh around 550 tons (1.2 million pounds) when it takes off, resulting in a really unusual payload ratio of around 1: 1700 or 0.06%. However, Falcon 9 will still have to work very hard to get IXPE into the correct orbit. This is because IXPE is designed to operate in an almost exactly equatorial orbit with a zero degree tilt.
Launch from Cape Canaveral, located at 28.5 degrees above the true equator, involves physical launch directly into an equatorial orbit of 0.2 degrees. Instead, a rocket must launch into a parking orbit in the east, then perform what’s called a plane or tilt shift once in space. Aircraft swaps are famous for being often (in terms of rocket performance) one of the most expensive maneuvers that can be performed in orbit. This is certainly the case for IXPE, which will require a 28.5 degree plane change shortly after takeoff.
For the Falcon 9 this means that even the tiny ~ 330kg IXPE is probably still around 20-30% of its maximum theoretical performance (1.5-2 tonnes) for such a mission profile, while the same rocket it is capable of launching itself. 15 tons (33,000 pounds) in the same 600-km (373-mile) orbit that the IXPE is targeting when it is not necessary to change planes. For example, for a NASA calculator With access to official performance data, Blue Origin claims that its gigantic New Glenn rocket, designed to launch more than 40 tons (~ 90,000 pounds) into low Earth orbit (LEO), can only launch about 2 tons (~ 4,500 pounds) than planned. IXPE. orbit
SpaceX is no stranger to launching an absurdly small NASA spacecraft, including the dual asteroid redirection test (DART) of around 700kg (~ 1,500lb) last month, but IXPE, about 10% more. lightweight than TESS, it will be the smallest dedicated. payload never launched by Falcon 9. After launch, the Falcon 9 B1061 thruster will attempt with its fifth drone to land more than 650 km (400 miles) downstream. Demonstrating how the IXPE aircraft change makes an effortless launch to 600 km, an older and less capable Falcon 9 thruster landed just 300 km (185 miles) downstream after launching TESS into orbit and up to 375,000 km (233,000 miles), approximately the same distance between the Earth and the Moon.
The weather is currently 90% favorable for SpaceX’s IXPE launch on December 9.
