TRG – Telescope Review Guide

Sporting the classic long-tube Newtonian design, the Orion SpaceProbe 130 mm provides great all-around viewing performance. One minute you can be studying lunar crater formations at high power; the next, the ethereal glow of a nebular star factory. A few minutes later, the ringed visage of Saturn. All served in crisp detail by way of the Orion SpaceProbe’s light-gathering 130mm (5.1″) primary mirror of 900mm focal length (f/6.9).

The Orion SpaceProbe 130 ’s mirror lies at the base of the rolled-steel optical tube, which is outfitted with a smooth rack-and-pinion focuser. The Orion SpaceProbe 130 accepts 1.25″ eyepieces, including the two fully coated Explorer II eyepieces that come standard with the SpaceProbe 130mm: a 25mm for low-power viewing at 36x and a 10mm for higher-power looks at 90x. Also standard is a 6×30 achromatic finder scope to help home in on celestial targets.

The Orion SpaceProbe 130 comes on the sturdy EQ-2 equatorial model, with adjustable aluminum legs and accessory tray. Slow-motion controls allow fine manual pointing of the telescope and easy star tracking. Addition of an optional EQ-2M AstroTrack electronic drive enables the telescope to track objects automatically.

 The Orion SpaceProbe 130ST

The Orion SpaceProbe 130ST is a step up from the SpaceProbe 130 for the more serious beginning or intermediate stargazer who wants additional performance, particularly for targeting deep-sky objects.

The Orion SpaceProbe 130ST is indeed more compact than the standard Orion Space Probe model. The Orion Space Probe 130 ST’s optical tube measures 24″ long compared to 33″ on the standard Orion Space Probe 130. The focal length of the Orion Space Probe ST’s 130mm (5.1″) primary mirror is 650mm (f/5), yielding a wider field of view and brighter images for a given eyepiece focal length.

The Orion SpaceProbe 130ST has a primary diffraction-limited parabolic mirror, the same type used on much larger reflectors costing many times as much. On a short-focal-length design like this one, a parabolic mirror is a must for focusing incoming light to a point and delivering sharp, detailed images. Moreover, the secondary mirror of the Orion SpaceProbe 130ST is held in an advanced holder with thin 0.5mm metal vanes, to reduce diffraction spikes and light loss. These features combined with the included 25mm (26x) and 10mm (65x) Sirius Plössl eyepieces and quick-release 6×30 achromatic finder scope make this one sweet optical system for astronomy! It also includes a collimation cap and center-marked primary mirror for easy optical alignment.

The Orion SpaceProbe 130ST comes on an EQ-2 equatorial mount with dual setting circles and slow-motion hand controls. An optional EQ-2M or AstroTrack electronic drive can be added for automatic tracking. The adjustable aluminum tripod is strong yet lightweight and includes an accessory tray.

Whether you’re looking for a better-quality first telescope or a portable instrument to complement your big Dob, you’ll love the Orion SpaceProbe 130ST.

Next to last in my 6 part series on choosing your first telescope.

Telescope mountings

In the first four parts, I’ve discuse aperture, power and the different types of telescopes. Now I’d like to talk about an often overlooked but very important aspect of using a telescope – the mounting. A shaky view is all it takes to a fanatastic viewing session! A good mount can enhance your views. There are two basic telescope mountings:
ﾷ The equatorial and
ﾷ The altazimuth.
An equatorial mount is designed so you can easily track the motion of the sky as the Earth turns and its motions indicate celestial directions in the eyepiece. This helps when you’re trying to find your way among the stars with a map. The altazimuth mounts are simpler and just swing up, down, left and right. You have to move the scope along every so often to follow the stars, moons and planets. An altazimuth mount is both cheaper and lighter for the same degree of stability.

Come back for my concluding article when I’ll wrap everything up.