[ad_1]
The “space blimp” is a proposed cargo transportation system to low-Earth orbit. The design consists of three stages, with the first stage being a helium-filled aircraft that docks with a permanent crewed platform called the Dark Sky Station. The third stage is the orbital ascender, which is propelled by ion engines and solar panels. However, experts have raised concerns about the feasibility of the design.
Orbital airship, or “space blimp,” is a proposed means of moving cargo from the ground to low-Earth orbit without the use of conventional rockets. The design of an orbital aircraft consists of three stages, designed to move payloads from Earth to space in about a week. Although there are several organizations working to create such a ship, the concept is best known as part of a program called Airship to Orbit (ATO), devised by JP Aerospace, a California-based volunteer organization that sees itself as a NASA’s private competitor. Despite JP Aerospace’s enthusiasm for its proposed design, several experts conducting independent analysis have argued that certain details are physically unfeasible.
The ATO first stage is a conventional helium-filled aircraft. V-shaped for the purpose of being aerodynamic, it is labeled Ascender. The orbital aircraft ascends to approximately 40 kilometers (25 miles), then docks with stage two, a permanent crewed platform called the Dark Sky Station (DSS).
Like the Ascender, the Dark Sky Station is an inflated structure without a hard shell. The first stage is prevented from ascending beyond 25 miles (40 km) because any orbital aircraft capable of surviving atmospheric winds would unfortunately be too heavy to make the journey into space. Several Ascender and Dark Sky Station prototypes have already been created.
The third stage of ATO is the orbital ascender, a 6,000-foot (1.8 km) long spacecraft/aircraft designed to make the journey from DSS to 93 miles (150 km), or low-Earth orbit. Although helium is still lighter than air at 25 miles (40 km), this effect diminishes and eventually stops, making the ship heavier than its surroundings. At 93 miles (150 km) the air density is only three billionths of what it is at sea level.
JP Aerospace has proposed covering this massive Ascender in solar panels and using ion engines to accelerate the craft to about 5 miles per second (8,000 meters per second), the speed required for any object to reach orbit. It has been claimed that this process would take around five days.
Unfortunately, some simple calculations show that ion engines coupled with solar panels would not provide enough thrust to propel the massive envelope of gas at the speed required for atmospheric egress. Possibly by burning hydrogen on board, creating a blimp design that folds up during ascent to become more aerodynamic, or by emitting energy in the form of microwaves from the Dark Sky Station to the Orbital Ascender, this scheme could be practical. Alternatively, the Dark Sky Station could simply be used as a launch pad for chemical rockets.
Many details still need to be worked out for the orbital aircraft to be viable. No lighter-than-air craft have ever flown at hypersonic speeds, leading many experts to be skeptical of proposals for an orbital aircraft.
[ad_2]