SpaceX has not only made it possible for the USA to send back humans into space, but it also opened an opportunity for companies and scientific projects to reach space with a small price tag. What was almost unreachable due to being costly before, now it is possible and affordable.
Using its Falcon 9 launch vehicle, SpaceX offers launch opportunities to a Sun Synchronous Orbit ( a nearly polar orbit around our planet) for small satellites of about 50 Kg and with a price as low as $275, 000, with an additional cost of $5,500 per extra kg. These launches, known as Rideshare Missions, happen approximately every four months. The number of payload spacecraft per launch depends on their size and combined weight; however, the quarterly schedule for these launches offers plenty of opportunities for small spacecraft to go to space.
How does all this work? For these missions, SpaceX has a Launch Vehicle that includes CubeSat dispensers and small spacecraft standard mechanical interfaces 8”, 15”, or 24” in diameter that, within these specs, can accommodate Rideshare satellites of different sizes. However, for payloads that don’t meet these requirements, SpaceX also offers an alternative configuration. These payloads can include other small spacecraft payloads that require multiple deployments from the Launch Vehicle or can host several of these payloads in a Transfer Vehicle that will free them into space after it is released. In many cases, these are handled by companies that act as launch integrators who buy ports on SpaceX’s payload stack and then assemble multiple customers into that space. Sometimes, payloads have to wait up to one week to complete propulsive maneuvers or secondary deployments.
For all this to work, all payloads adhere to well-defined masses and dimensions. These also follow specified deployment maneuvers, separation attitudes, and specified velocities. Other requirements are avoiding specific propellants and construction materials and using specific fasteners and cables.
Rideshare also offers a solution for medium-class spacecraft with weights between 500 Kg and 2500 Kg. These are separated from the rest of the payloads and are called Cake Topper because the payload is located on the forward end of a rideshare hardware stack. Because of the larger size, this type of Rideshare payload has many of the capabilities of a primary, dedicated mission but it can be set up to deploy within a two-orbit drop-off to ensure co-payloads can deploy as a standard Rideshare program.
Up to now, there have been six of these programs. In January 2023, SpaceX launched the 6th transporter mission carrying 114 small satellites and other payloads. Coincidentally, this was also the 200th successful flight of SpaceX. The payloads for this mission ranged in size from picosatellites of less than a kilogram and measuring only a few centimeters on each side, to microsatellites with masses of around 100 kg.
The low cost opened opportunities for small companies to launch satellites for earth studies or satellite imagery for diverse uses like supporting agriculture, business development, enhancing activities like search and rescue, and much more. However, there are other payloads with less purposeful objectives. It would be interesting to see how these are currently regulated. A new topic I will research in the near future.