Pegasus – The Air Launched Rocket
Boosted Into Space
The Pegasus rocket is unique as it is launched from the belly of an aircraft high above Earth and yet can place small satellites of over 440 kilograms into low Earth orbit. It comprises three solid rocket stages and had its first flight in 1990 completing a total of 44 flights as at early 2018!
Interesting Facts About The Pegasus Rocket!
- The rocket was developed by Orbital ATK (who also launches Antares) and first flew in 1990 when Pegasus was dropped from an Air Force B-52! Later Orbital ATK would convert a former passenger airliner, called ‘Stargazer’, to do this.
- The names Stargazer and Pegasus are named after starships that featured in the TV series Star Trek.
- The Pegasus is small by orbital-class rocket standards, with even the larger XL version only having an initial weight of 23 tonnes, a length of 17.6 m and a wingspan of just 6.7 m.
- The Pegasus is made up of 3 solid rocket stages with wings on its first stage (which rockets don’t usually have) to gain lift during its initial atmospheric flight.
- The real benefit of using a carrier aircraft, despite launching the rocket from a small fraction of its final height and speed, is reducing cost. Without the air launch, you’d need a more expensive (and complicated) rocket, ground launch facilities and insurance costs. In addition, launching from the air near the equator dramatically increases the payload to orbit performance and lower costly weather delays!
- A typical Pegasus launch occurs as follows;
- The Stargazer carrier aircraft takes off like any other plane and once at the correct altitude and location releases the Pegasus rocket
- Pegasus free-falls for 5 seconds to separate from the carrier
- The solid rocket first stage lights and the rocket pitches up at 45-degree with the wings and fins providing lift and steering control
- Once the first stage burns out, the rocket is at over 200,000 feet (61 km) the first stage separates
- The second stage then ignites for another 78 seconds before separating too
- The fairing then separates and the third stage continues to place the payload into the correct orbit!
- For the first few years the rocket was plagued by several failures, but by 1997 the launches have been largely successful with 38 of the 43 total flights considered successful.
- Despite initially being as low as $6 million US dollars the current version costs closer to $50 million to launch – getting to space is an expensive business!