More ultralight launch vehicles
The proliferation of rocket startups has led to an anecdotal situation. On a fine day, journalists from ABC7News flew a helicopter over the city of Alameda (San Francisco Bay, California), when the pilot noticed a real rocket below. It turned out this is another private rocket company with the appropriate name Stealth Space on the sly tested its launch vehicle. And, judging by the layer of burning near the stand, not for the first time.

Frame from ABC7 video
Here is the ABC7 report. It’s funny that they didn’t manage to talk with the company’s representatives, so the comments are given by the staff of the local brewery.
Nevertheless, journalists managed to find out the name of the rocket - Astra and its official characteristics in comparison with other launch vehicles.

You can also find a NASA contract with the company Astra Space (judging by the coincidence of the city, it is the same company) for the development and flight tests of the launch vehicle on engines with electric fuel supply. Thus, the mysterious rocket is a direct analogue and competitor of the Electron Rocket Lab.
The video is completely incomprehensible number of steps in the "Astra". This may be a single-stage geophysical rocket, and a 2-3 stage booster. The only thing that can be seen is a rather unusual number and location of the engines - there are five of them, and they are installed in a circle.

Frame from ABC7 video
No matter how secretive Astra Space or Stealth Space employees are, over time we will learn more about their rocket. But the wait will not be boring, companies that create ultralight rockets, now surprisingly a lot.
The first launch of the Firefly Alpha carrier rocket was scheduled for March 2018 (this date is still shown in the video on the official YouTube channel), but according to news from the end of 2017, it has already moved down to 2019. This is a relatively large rocket that will have to output one ton. payload to a low orbit or 600 kg to a sun-synchronous orbit. The engines are used quite ordinary - oxygen-kerosene open cycle, but in the design, like on the rocket "Electron", are going to widely use composite materials.

PH Firefly Alpha, screenshot from the official site.
On the official YouTube channel, you can look at the engine tests.
Vector rocket began to experience in 2017, and it has already managed to make two suborbital flights. In geophysical modification, it has a single engine worth 2.7 tons. The light version of the Vector-R with three engines in the first stage will have to output 66 kg, and the heavy one with six engines - 110 kg to a low orbit. The startup impresses with the appearance of the engines - it feels like they were made by hand. Officially, by the way, 3D printing and only 15 details are declared.

Photo by Michael Howar / Spaceflight Insider
Second launch video.
A very unusual way to send a payload into space is offered by Zero2Infinity. The three-stage launch vehicle will rise on a helium stratostat and turn on engines already at an altitude of about 30 km. A payload of 150 kg and re-use of all stages are claimed (which will be very difficult to do for the third stage, which will have to return from orbit).

Screenshot from the official website
Animation Mission.
In 2017, the company conducted tests in which the engine was turned on for a few seconds and reached a speed of 61 m / s.
Despite the fact that the rise of the rocket into the stratosphere makes the way to space a little easier, you should not overestimate this idea. Orbit is speed, not altitude, and for air start systems it is much more important to accelerate in the atmosphere with free oxygen than to rise higher.
The Virgin Group conglomerate is engaged not only in suborbital tourism (Virgin Galactic, SpaceShipTwo), but also in launching satellites (Virgin Orbit, LauncherOne). Here, too, it is planned to use an air launch, the Boeing-747 was chosen as the carrier, which will have to launch a two-stage rocket with oxygen-kerosene engines and a carrying capacity of 200 kg. Test flights are expected this year.
An animation of the mission.
Many companies that implement a variety of approaches to making space more accessible are wonderful, and it will be very interesting to watch them. The path to space is complex and thorny, and not everyone was able to go through it. Good luck to new players in the private space market.

Frame from ABC7 video
Here is the ABC7 report. It’s funny that they didn’t manage to talk with the company’s representatives, so the comments are given by the staff of the local brewery.
Nevertheless, journalists managed to find out the name of the rocket - Astra and its official characteristics in comparison with other launch vehicles.

You can also find a NASA contract with the company Astra Space (judging by the coincidence of the city, it is the same company) for the development and flight tests of the launch vehicle on engines with electric fuel supply. Thus, the mysterious rocket is a direct analogue and competitor of the Electron Rocket Lab.
The video is completely incomprehensible number of steps in the "Astra". This may be a single-stage geophysical rocket, and a 2-3 stage booster. The only thing that can be seen is a rather unusual number and location of the engines - there are five of them, and they are installed in a circle.

Frame from ABC7 video
No matter how secretive Astra Space or Stealth Space employees are, over time we will learn more about their rocket. But the wait will not be boring, companies that create ultralight rockets, now surprisingly a lot.
Alpha firefly
The first launch of the Firefly Alpha carrier rocket was scheduled for March 2018 (this date is still shown in the video on the official YouTube channel), but according to news from the end of 2017, it has already moved down to 2019. This is a relatively large rocket that will have to output one ton. payload to a low orbit or 600 kg to a sun-synchronous orbit. The engines are used quite ordinary - oxygen-kerosene open cycle, but in the design, like on the rocket "Electron", are going to widely use composite materials.

PH Firefly Alpha, screenshot from the official site.
On the official YouTube channel, you can look at the engine tests.
LLC "Vector"
Vector rocket began to experience in 2017, and it has already managed to make two suborbital flights. In geophysical modification, it has a single engine worth 2.7 tons. The light version of the Vector-R with three engines in the first stage will have to output 66 kg, and the heavy one with six engines - 110 kg to a low orbit. The startup impresses with the appearance of the engines - it feels like they were made by hand. Officially, by the way, 3D printing and only 15 details are declared.

Photo by Michael Howar / Spaceflight Insider
Second launch video.
Blown star
A very unusual way to send a payload into space is offered by Zero2Infinity. The three-stage launch vehicle will rise on a helium stratostat and turn on engines already at an altitude of about 30 km. A payload of 150 kg and re-use of all stages are claimed (which will be very difficult to do for the third stage, which will have to return from orbit).

Screenshot from the official website
Animation Mission.
In 2017, the company conducted tests in which the engine was turned on for a few seconds and reached a speed of 61 m / s.
Despite the fact that the rise of the rocket into the stratosphere makes the way to space a little easier, you should not overestimate this idea. Orbit is speed, not altitude, and for air start systems it is much more important to accelerate in the atmosphere with free oxygen than to rise higher.
Rocket Carrier One
The Virgin Group conglomerate is engaged not only in suborbital tourism (Virgin Galactic, SpaceShipTwo), but also in launching satellites (Virgin Orbit, LauncherOne). Here, too, it is planned to use an air launch, the Boeing-747 was chosen as the carrier, which will have to launch a two-stage rocket with oxygen-kerosene engines and a carrying capacity of 200 kg. Test flights are expected this year.
An animation of the mission.
Conclusion
Many companies that implement a variety of approaches to making space more accessible are wonderful, and it will be very interesting to watch them. The path to space is complex and thorny, and not everyone was able to go through it. Good luck to new players in the private space market.